The invention discloses an anti-theft lock. The anti-theft lock comprises a lock shell and a lock cylinder. A lock shell hole and a lock shell groove are formed in the lock shell. The lock groove is formed in the side wall of the lock shell hole. The lock cylinder is arranged in the lock shell hole and can rotate freely in the lock shell hole. Marble grooves, a lock rod groove and a lock plate groove are formed in the side wall of the lock cylinder. The multiple marble grooves are formed in the lock cylinder. A marble assembly is arranged in each marble groove. Each marble assembly comprises a marble rod and a spring. A lock plate is arranged in the lock plate groove. The lock plate is in contact with the marble rods. Containing grooves are formed in each marble rod. A lock rod is arranged in the lock rod groove. The lock rod is in contact with the lock plate. The lock rod enters or protrudes out of the surface of the lock cylinder under the effect of the lock plate. By the adoption of the anti-theft lock, the key quantity is increased, the technical unlocking can be prevented effectively, and the safety performance is enhanced greatly; and besides, the marbles are designed in a rod shape, the strength is larger, the situation that the lock cylinder is twisted forcedly with a tool and the marble assemblies in the lock are catastrophically destroyed is avoided, and thus the forced unlocking is prevented effectively.