If my system hardware is not stable,can I use SSD to be the windows SYSTEM disk?

Hello, 

of course the ssd will also be damaged if the system keeps crashing and you terminate the power of the computer many times, you will also see the unexpected power loss counter in the ssd dashboard of the ssd to grow in the smart attributes that means that it affects the life endurance of the ssd. 

so i would suggest not to overclock at this point where the system will start ot crash.