Inclined - shaft man - trip 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 man - trip car,it is need to do periodically full - speed unhooking test. Based on the inductive summary of test work on man - trip car,this paper redefines the concept of full speed for full speed unhooking test of man - trip car,defines the maximum permissible deviation of initial velocity for the field testing of inclined - shaft man - trip car.