The invention provides a self-oriented large-fault-tolerance isomorphic interface for a spacecraft and a using method thereof. A gear wheel is driven to rotate by a motor by means of a worm, a supporting sleeve is driven to rotate by the gear wheel by means of a gear wheel key, the supporting sleeve rotates to drive an inner rotating cylinder to rotate firstly, for the movement of the inner rotating cylinder, a guide plate is pushed out through a meshed guide plate driving rod, a guide plate pushing rod and a rotating pin, meanwhile, a locking positioning pin is pushed out by the supporting sleeve, after the locking positioning pin and the supporting sleeve reach a limit station, the motor stops, after the interface is aligned, the motor is started again, the supporting sleeve drives a meshed telescopic sleeve to move through the driving rod, and a connecting key is used for clamping a concave part of the locking sleeve so as to complete locking. According to the interface and the method in the invention, self-oriented fault-tolerant butt joint with large butt joint initial deviation between spacecrafts can be achieved, multi-angle butt joint under the condition of multi-face connection is achieved, the interface structure is simple, the locking force is large, the size is compact, and high-reliability and large-fault-tolerance butt joint of the spacecraft can be met; meanwhile, the control is simple, the energy consumption is low, and the task cost of actual spacecraft butt joint can be saved.