如前所述，size属性是您所需要的。要在打印时设置页面的方向和大小，您可以使用以下命令:

/* ISO Paper Size */
@page {
  size: A4 landscape;
}

/* Size in mm */    
@page {
  size: 100mm 200mm landscape;
}

/* Size in inches */    
@page {
  size: 4in 6in landscape;
}

下面是@page文档的链接。

我曾经尝试解决这个问题，但我所有的研究都将我引向了ActiveX控件/插件。浏览器(至少在3年前)没有允许更改任何打印设置(副本数量，纸张大小)的技巧。

我努力提醒用户，当浏览器打印对话框出现时，他们需要选择“横向”。我还创建了一个“打印预览”页面，这比IE6的要好得多!我们的应用程序在一些报告中有非常宽的数据表，打印预览会清楚地告诉用户什么时候表格会溢出纸张的右边缘(因为IE6也不能处理2张纸的打印)。

是的，人们至今仍在使用IE6。

你可以使用css2 @page规则，它允许你将“size”属性设置为横向。

引用自css - discussion Wiki

The @page rule has been cut down in scope from CSS2 to CSS2.1. The full CSS2 @page rule was reportedly implemented only in Opera (and buggily even then). My own testing shows that IE and Firefox don't support @page at all. According to the now-obsolescent CSS2 spec section 13.2.2 it is possible to override the user's setting of orientation and (for example) force printing in Landscape but the relevant "size" property has been dropped from CSS2.1, consistent with the fact that no current browser supports it. It has been reinstated in the CSS3 Paged Media module but note that this is only a Working Draft (as at July 2009). Conclusion: forget about @page for the present. If you feel your document needs to be printed in Landscape orientation, ask yourself if you can instead make your design more fluid. If you really can't (perhaps because the document contains data tables with many columns, for example), you will need to advise the user to set the orientation to Landscape and perhaps outline how to do it in the most common browsers. Of course, some browsers have a print fit-to-width (shrink-to-fit) feature (e.g. Opera, Firefox, IE7) but it's inadvisable to rely on users having this facility or having it switched on.

你可以尝试以下方法:

@page {
    size: auto
}

-webkit-transform: rotate(-90deg); -moz-transform:rotate(-90deg);
     filter:progid:DXImageTransform.Microsoft.BasicImage(rotation=3);

在Firefox 16.0.2中不能运行，但在Chrome中可以运行