The invention relates to an intelligent anti-theft mechanical lock, belonging to the technical field of anti-theft lock technology. The intelligent anti-theft mechanical lock is safe, reliable and relatively convenient to operate and can be unlocked by unlocking a doorknob after a key is inserted; a lock cylinder and a lock body are connected through a square connecting sleeve; a square rotating shaft is arranged in the square connecting sleeve; and the key is inserted into the lock cylinder, and the positions of the key and a lock cylinder push rod are matched so as to control the movement distance of the lock cylinder push rod, and then the doorknob is unlocked by rotating, so that the lock cylinder push rod stops pushing of an elastic pin, thus achieving the purpose of unlocking. The lock is easy to operate, convenient to use, safe and reliable, capable of effectively preventing the technical unlocking, and widely used in a variety of security locks, safe boxes and the like.