对我来说，这些简单的scss规则非常有效:

.modal.show{
  z-index: 1041;
  ~ .modal.show{
    z-index: 1043;
  }
}
.modal-backdrop.show {
  z-index: 1040;
  + .modal-backdrop.show{
    z-index: 1042;
  }
}

如果这些规则导致错误的模态在你的情况下，要么改变你的模态div的顺序，或者在上面的scss中改变(奇数)为(偶数)。

我意识到一个答案已经被接受，但我强烈建议不要破解bootstrap来解决这个问题。

通过连接show .bs.modal和hidden.bs.modal事件处理程序并在那里调整z-index，可以很容易地达到同样的效果。

下面是一个工作示例

更多信息可以在这里找到。

这个解决方案自动工作于任意深度的堆栈模态。

脚本源代码:

$(document).ready(function() {

    $('.modal').on('hidden.bs.modal', function(event) {
        $(this).removeClass( 'fv-modal-stack' );
        $('body').data( 'fv_open_modals', $('body').data( 'fv_open_modals' ) - 1 );
    });

    $('.modal').on('shown.bs.modal', function (event) {
        // keep track of the number of open modals
        if ( typeof( $('body').data( 'fv_open_modals' ) ) == 'undefined' ) {
            $('body').data( 'fv_open_modals', 0 );
        }

        // if the z-index of this modal has been set, ignore.
        if ($(this).hasClass('fv-modal-stack')) {
            return;
        }

        $(this).addClass('fv-modal-stack');
        $('body').data('fv_open_modals', $('body').data('fv_open_modals' ) + 1 );
        $(this).css('z-index', 1040 + (10 * $('body').data('fv_open_modals' )));
        $('.modal-backdrop').not('.fv-modal-stack').css('z-index', 1039 + (10 * $('body').data('fv_open_modals')));
        $('.modal-backdrop').not('fv-modal-stack').addClass('fv-modal-stack'); 

    });        
});

没有脚本解决方案，只使用css给你有两层情态，设置第2个情态为更高的z索引

.second-modal { z-index: 1070 }

div.modal-backdrop + div.modal-backdrop {
   z-index: 1060; 
}

这段代码非常适合用于引导4。其他代码中的问题是如何选择模态背景。这将是更好的，如果你使用jQuery的下一个选择在实际的模态已经显示。

(文档)。(“show.bs美元。模态”、“。Modal '， function () { var zIndex = 1040 + (10 * $('.modal').length); Var模型= $(this); model.css (z - index, zIndex); 模型。attr (data-z-index, zIndex); })； (文档)。(“shown.bs美元。模态”、“。Modal '， function () { Var模型= $(this); var zIndex = model.attr('data-z-index'); model.next('.modal- background .show').css('z-index'， zIndex - 1); })；

如果你正在寻找Bootstrap 4的解决方案，有一个简单的使用纯CSS:

.modal.fade {
    background: rgba(0,0,0,0.5);
}

更新日期:2019年1月22日，13.41 我通过jhay优化了解决方案，它还支持关闭和打开相同或不同的对话框，例如，从一个细节数据向前或向后跨步到另一个细节数据。

(function ($, window) {
'use strict';

var MultiModal = function (element) {
    this.$element = $(element);
    this.modalIndex = 0;
};

MultiModal.BASE_ZINDEX = 1040;

/* Max index number. When reached just collate the zIndexes */
MultiModal.MAX_INDEX = 5;

MultiModal.prototype.show = function (target) {
    var that = this;
    var $target = $(target);

    // Bootstrap triggers the show event at the beginning of the show function and before
    // the modal backdrop element has been created. The timeout here allows the modal
    // show function to complete, after which the modal backdrop will have been created
    // and appended to the DOM.

    // we only want one backdrop; hide any extras
    setTimeout(function () {
        /* Count the number of triggered modal dialogs */
        that.modalIndex++;

        if (that.modalIndex >= MultiModal.MAX_INDEX) {
            /* Collate the zIndexes of every open modal dialog according to its order */
            that.collateZIndex();
        }

        /* Modify the zIndex */
        $target.css('z-index', MultiModal.BASE_ZINDEX + (that.modalIndex * 20) + 10);

        /* we only want one backdrop; hide any extras */
        if (that.modalIndex > 1) 
            $('.modal-backdrop').not(':first').addClass('hidden');

        that.adjustBackdrop();
    });

};

MultiModal.prototype.hidden = function (target) {
    this.modalIndex--;
    this.adjustBackdrop();

    if ($('.modal.in').length === 1) {

        /* Reset the index to 1 when only one modal dialog is open */
        this.modalIndex = 1;
        $('.modal.in').css('z-index', MultiModal.BASE_ZINDEX + 10);
        var $modalBackdrop = $('.modal-backdrop:first');
        $modalBackdrop.removeClass('hidden');
        $modalBackdrop.css('z-index', MultiModal.BASE_ZINDEX);

    }
};

MultiModal.prototype.adjustBackdrop = function () {        
    $('.modal-backdrop:first').css('z-index', MultiModal.BASE_ZINDEX + (this.modalIndex * 20));
};

MultiModal.prototype.collateZIndex = function () {

    var index = 1;
    var $modals = $('.modal.in').toArray();


    $modals.sort(function(x, y) 
    {
        return (Number(x.style.zIndex) - Number(y.style.zIndex));
    });     

    for (i = 0; i < $modals.length; i++)
    {
        $($modals[i]).css('z-index', MultiModal.BASE_ZINDEX + (index * 20) + 10);
        index++;
    };

    this.modalIndex = index;
    this.adjustBackdrop();

};

function Plugin(method, target) {
    return this.each(function () {
        var $this = $(this);
        var data = $this.data('multi-modal-plugin');

        if (!data)
            $this.data('multi-modal-plugin', (data = new MultiModal(this)));

        if (method)
            data[method](target);
    });
}

$.fn.multiModal = Plugin;
$.fn.multiModal.Constructor = MultiModal;

$(document).on('show.bs.modal', function (e) {
    $(document).multiModal('show', e.target);
});

$(document).on('hidden.bs.modal', function (e) {
    $(document).multiModal('hidden', e.target);
});}(jQuery, window));