Website ie8 incompatibility problem_html/css_WEB-ITnose

The website I made shows no problem in Firefox, Google, and 360. However, the layout of IE8 is messed up. It is very messy and cannot be viewed.
I want to modify it, but I can’t find the cause of the problem. I don’t know where to start. Change it
I would like to ask you if there are any tools or methods to find out the incompatibility of ie8 and then modify it. Thank you very much

Reply to the discussion ( Solution)

It’s usually a css problem. This requires improving the level of CSS usage. Or search for articles on the Internet about CSS compatibility summary

It is generally believed that the root cause of compatibility problems is: your structure is unreasonable, specifically, letting a div bear too much, decoration, etc. Other attributes. Then the reference method is to look at other people's websites and see how they divide the structure and write styles. Especially portal application websites like Taobao, Tencent, etc.
The tool firebug is a powerful tool,
http://www.cnblogs.com/jikey/p/3607133.html
There are several related URLs here, take a look.
Use of firebug and chrome debugging tools.