实这个很简单的只要更改php.ini里三个配置即可。(见下面加粗部分，改成你自己的需求即可)
; Maximum allowed size for uploaded files.
; http://php.net/upload-max-filesize
;upload_max_filesize = 2M
upload_max_filesize = 300M
; Maximum amount of memory a script may consume (128MB)
; http://php.net/memory-limit
;memory_limit = 128M
memory_limit = 300M
; Maximum size of POST data that PHP will accept.
; http://php.net/post-max-size
;post_max_size = 8M
post_max_size = 300M