The utility model discloses a mechanical arm detaching clamp. The clamp comprises a load-bearing rod and a plurality of detaching units which are sequentially fixed on the load-bearing rod from the top to the bottom. Each detaching unit comprises a clamping jaw pair, a first sliding track and a first driving device, the length direction of the first sliding track is arranged along the direction which is vertical to the load-bearing rod, the clamping jaw pair comprises two clamping jaws which are oppositely arranged, the two clamping jaws which are oppositely arranged are both connected to the first sliding track in a sliding manner, and the two clamping jaws which are oppositely arranged can open and close to clamp and release a silicon rod; the length of the first sliding track is set so that the mechanical arm detaching clamp can detach the silicon rod in a vertical way or a parallel way through movement of the clamping jaw pair on the first sliding track. Through the mechanical arm detaching clamp, the situation of frequently replacing the clamp is avoided in the production process, the coherence and efficiency of operation are improved and the production efficiency of a finished product of polycrystalline silicon is further improved.