这是一个众所周知的问题，但由于某种原因，自2013年以来一直没有得到解决

https://core.trac.wordpress.org/ticket/22363

/**
 * Sanitize filename to not brake links with UTF-8 characters
 *
 * WordPress allow to upload files with names containing UTF-8 characters. Some
 * browsers do not handle properly UTF-8 characters in url which causes 404 errors.
 * This filter will remove UTF-8 characters from filename before saving it.
 * 
 * @see https://core.trac.wordpress.org/ticket/22363 Bug request
 *
 * @param string $filename Filename
 *
 * @return string Sanitized filename
 */
function sanitize_filename( $filename ) {
    $file_parts = explode( \'.\', $filename );
    $extension  = array_pop( $file_parts );
    $filename   = sanitize_title( preg_replace( \'/[^A-Za-z0-9\\-]/\', \'\', join( \'.\', $file_parts ) ) );

    return sprintf(\'%s.%s\', $filename, $extension);
}

add_filter( \'sanitize_file_name\', \'sanitize_filename\' );