Inclined - shaft mantrip car is a kind of mechanical equipment being usually used for personal transportation in mine. In order to insure the operation security and reliability of mantrip car,it is need to do periodically full-speed unhoo-king test,so as to confirm the parking brake performance of inuse man-trip car. Based on the analyses on braking deceleration and the inductive summary of test results,this paper defines the concept of braking deceleration,and determines the technological index about average braking deceleration for the unhooking test of inclined-shaft man-trip car.