The present invention relates to a surgical screw capable of self-locking and a fusion device using the same. The screw includes: a screw body having a body main thread formed on an outer circumferential surface thereof, a body locking thread spaced apart from the body main thread with an offset portion interposed therebetween, and a body driving groove formed in the upper portion thereof; and a sleeve having a sleeve thread formed on an inner circumferential surface thereof to be screwed with the body locking thread, and a sleeve stopper spaced downwards from the sleeve thread so as to support the body locking thread. The surgical screw may also be included in a fusion device in a different form by coupling with a plate or a cage.