Can I use my android phone as finger print, webcam, and mic for my windows 10PC? I suppose I can buy a mic, a webcam, and a finger print censor for my windows 10.

But I have all those in android phone already.

Is there an easy way to do so?
As for the camera and mic part,

If you simply search the web for phrases like "use Android camera/mic on PC", you will come across many apps; some of them actually do the job.

I have used an app called DroidCam in the past which had worked for me in Windows 7 after a litte bit of struggling. (I have never tried it in Windows 10, though; but I guess it should work)


As for the fingerprint reader part,

There is not a solution which can be assured to work flawlessly. But there are some things which might be helpful :-


Dynamic Lock by Microsoft — If you are simply looking for a solution to unlock your PC using your phone, then this might be the solution for you. Although it doesn't specifically use a fingerprint unlock, it allows you to keep your PC unlocked when your phone is close enough and reachable via Bluetooth.
Third-party solution — There is an app called Remote Fingerprint Unlock which is slightly complicated to set up but will do the job for you.
Samsung Flow — If you happen to have a Samsung Android phone, then this solution from Samsung should work for you. 
This app has also been ported to non-Samsung devices by some developer(s) but the Fingerprint unlock functionality does not work on non-Samsung devices yet.


(Mentioning the below content just for the sake of completeness; doesn't answer this question) 


Google Smart Lock for Chromebooks — This is a solution provided by Google to unlock your PC with a fingerprint scanner on your phone. However this only works on Chrome OS (v71+) and not on any other OS.