httpd.conf中需要添加一行：

AllowEncodedSlashes On

The AllowEncodedSlashes directive allows URLs which contain encoded path separators (%2F for / and additionally %5C for \ on according systems) to be used. Normally such URLs are refused with a 404 (Not found) error.

参考信息：

http://httpd.apache.org/docs/2.0/mod/core.html#allowencodedslashes

http://blog.dynom.nl/archives/Apaches-fail-with-encoded-slashes2009062540.html