默认的firefox是不能自定义增加搜索引擎，当然有https://mycroftproject.com网站可以添加，但是那种都不如自定义来的好用。

1）about:config中，输入：browser.urlbar.update2.engineAliasRefresh，选择布尔值，设置为true
2）进入firefox设置，这时候搜索引擎就出现了增加按钮，然后就可以根据自己需要增加了。关键词为%s
3）备份自己的常用引擎：

bd=https://www.baidu.com/baidu?wd=%s
db=https://search.douban.com/movie/subject_search?search_text=%s
jd=https://search.jd.com/Search?keyword=%s
tm=https://list.tmall.com/search_product.htm?q=%s
imdb=https://www.imdb.com/find?q=%s
zh=https://www.zhihu.com/search?type=content&q=%s
fyz=https://translate.google.com/?hl=zh-CN&sl=auto&tl=zh-CN&text=%s%0A&op=translate
fye=https://translate.google.com/?hl=zh-CN&sl=auto&tl=en&text=%s%0A&op=translate
wb=https://s.weibo.com/weibo/%s?topnav=1&wvr=6&b=1
gg=https://www.google.com/search?q=%s
bili=https://search.bilibili.com/all?keyword=%s
git=https://github.com/search?q=%s
tube=https://www.youtube.com/results?search_query=%s
tb=https://s.taobao.com/search?q=%s
ali=https://aliso.cc/s/%s-1-0.html
wk=https://zh.wikipedia.org/wiki/%s
bing=https://cn.bing.com/search?q=%s

ago自定义搜索备份

bd=https://www.baidu.com/baidu?wd={query}
db=https://search.douban.com/movie/subject_search?search_text={query}
jd=https://search.jd.com/Search?keyword={query}
tm=https://list.tmall.com/search_product.htm?q={query}
imdb=https://www.imdb.com/find?q={query}
zh=https://www.zhihu.com/search?type=content&q={query}
fyz=https://translate.google.com/?hl=zh-CN&sl=auto&tl=zh-CN&text={query}%0A&op=translate
fye=https://translate.google.com/?hl=zh-CN&sl=auto&tl=en&text={query}%0A&op=translate
wb=https://s.weibo.com/weibo/{query}?topnav=1&wvr=6&b=1
gg=https://www.google.com/search?q={query}
bili=https://search.bilibili.com/all?keyword={query}
git=https://github.com/search?q={query}
tube=https://www.youtube.com/results?search_query={query}
tb=https://s.taobao.com/search?q={query}
ali=https://aliso.cc/s/{query}-1-0.html
wk=https://zh.wikipedia.org/wiki/{query}
bing=https://cn.bing.com/search?q={query}