在the_excerpt（）中显示完整帖子

This will set word limit on the_excrept() to 9999:

function new_excerpt_length($length) {
    return 9999;
}
add_filter('excerpt_length', 'new_excerpt_length');

It works to show a pretty big excerpt but it's a bad solution to my problem when all I wan't to do is to show all words from the_post() in the_excerpt(). Anyone who can help me with this?

Than why don't u use. the_content(); function it will show full content of post.

check reference here

http://codex.wordpress.org/Function_Reference/the_content

An excerpt is a short extract from a post. If you want to show the entire post content then you're using the wrong function.

Replace the_excerpt() with the_content().

If there's some reason you want to show all the post content inside the_excerpt() you could use:

function wpse_replace_excerpt_with_content( $excerpt ) {
    return get_the_content();
}
add_filter( 'the_excerpt', 'wpse_replace_excerpt_with_content' );

I can't imagine why you'd want to do this but it is possible.