推荐几个比较常用的字体icon设计，希望对你有帮助
http://fortawesome.github.io/Font-Awesome/
http://dryicons.com/
http://materialdesignicons.com/
http://modernuiicons.com/
http://xpressengine.github.io/XEIcon/library_common.html
http://loading.io/
https://icomoon.io/
https://material.io/icons/
https://feathericons.com/
https://akveo.github.io/eva-icons/#/
https://www.ikonate.com/
https://remixicon.com/
https://getavatars.app/