Downhole mechanical fishing spear

The utility model discloses a downhole mechanical fishing spear used for petroleum industry which is applicable for off operation and fishing hanging operation process of a downhole string, a packer, and other equipments. The downhole mechanical fishing spear of the utility model consists of a working barrel and a joint which are used cooperately. The working barrel is connected with a bottom end of a pipe string. The joint is connected to a top of a borehole string which needs a fishing spear or a tool. The working barrel consists of a top joint, a fishing claw and a protecting jacket. The top joint is connected with the fishing claw. The joint consists of a head and a fishing rod. The fishing rod is equipped on the head. The downhole mechanical fishing spear of the utility model saves payment of vehicle labor services without pumping vehicle and other vehicles for cooperately working, saves working hour, has a low sealing requirement for string, generates no fishing failure phenomenon with an oil pipe leakage, and reduces production cost and worker labor intensity.