The invention relates to the field of machining instruments and the field of electric tools, in particular to a self-tightening drill chuck with gears. The self-tightening drill chuck comprises a rear pressing cover, a rear body, a main body, a front sleeve, clamping jaws and driven bevel gears, wherein the rear body is arranged inside the main body; a driving bevel gear is arranged at one end of the rear body; the large end of the driving bevel gear is arranged close to the rear body; the driving bevel gear is arranged inside the main body and meshes with the driven bevel gears; the multiple driven bevel gears are uniformly arranged with the axis of the driving bevel gear as the center line; internal threads are arranged inside internal holes of the driven bevel gears; external threads used in cooperation with the internal threads are arranged at one ends of the clamping jaws; the main body is provided with clamping jaw holes and bevel gear holes; one end of the main body is fixedly arranged inside the front sleeve, and the other end of the main body is provided with a rear hole and the rear pressing cover; the rear pressing cover, the rear body, the driving bevel gear, the main body and the front sleeve are coaxially arranged; the internal threads and the external threads are multiple threads. The drill chuck can be conveniently loosened after clamping objects and being closed and can be opened manually, and the operation is simple and convenient.