nginx配置：
location ~ /(mmbiz|sz_mmbiz)(.*)/ {
proxy_pass https://mmbiz.qpic.cn;
proxy_set_header Host "mmbiz.qpic.cn"; #微信平台域名
proxy_set_header Referer "";
proxy_buffer_size 128k; #缓存区设置，不加的话，图片过大可能造成第一次加载失败
proxy_buffers 32 128k;
proxy_busy_buffers_size 128k;
expires 365d;
valid_referers none blocked *.xxxx.xxxx.com; #只允许xxx域名
if ($invalid_referer) {
return 404;
}
}
sub_filter "http://mmbiz.qpic.cn" "";
sub_filter_once off;
