Crystal fixing device on inner circle cutting machine

The utility model relates to a crystal fixing device on an inner circle cutting machine, which comprises a base, a fixing platform, a lifting mechanism and a fastening mechanism, the lifting mechanism is used for driving the fixing platform to do lifting motion relative to the base, and the fastening mechanism comprises a plurality of groups of clamping jaw assemblies and centering moving assemblies which are in one-to-one correspondence. And the centering moving assembly is used for driving the clamping jaw assembly to move on the fixed platform so as to clamp the crystal. The height of the fixed platform relative to the base can be adjusted through the lifting mechanism, cutting machining is facilitated, meanwhile, the clamping jaw assembly can abut against the clamping pieces in a one-to-one mode through the mode that the clamping pieces are arranged and the piston rods are additionally arranged, so that the clamping pieces firmly clamp crystals, and the working efficiency is improved. Even for irregular c