这些是png图片
- http://pngimg.com/
- https://www.stickpng.com/
- https://www.freepngs.com/
- http://www.pngall.com/
- http://www.pngmart.com/
- https://www.freepik.com/
这些是关于小图标
- https://www.easyicon.net/
- https://www.iconfont.cn/
- https://icons8.com/
- http://www.peakpx.com/
- http://www.bitbug.net/
- https://www.iconninja.com/
这些是关于logo
- https://www.logosc.cn/
- http://www.logofree.cn/
- https://www.logoaa.com/
- https://www.logogenie.net/
- https://www.logaster.cn/
- http://www.uugai.com/
这些是没分类的
- https://visualhunt.com/
- http://699pic.com/?sem=1
- https://www.pexels.com/
- https://unsplash.com/
- https://stocksnap.io/
- https://www.pexels.com/@creative-vix
- http://streetwill.co/
- https://gratisography.com/
- https://www.textures.com/
- https://pixabay.com/