The utility model discloses an integrated transmission case of a machine tool. Two sets of opposite one-way transmission devices are adopted, quick retreating and slow feeding of the machine tool are realized through a simple structure, and a simple structure, low manufacturing cost, low failure rate and low maintenance cost are achieved. By adopting the entire transmission case, the requirement on output of different rotating speeds through positive and negative mechanical rotation can be completed integrally. Meanwhile, a torsion clutch is arranged between the power system of the machine tool and the executing device of the machine tool, so that torque on a transmission shaft is increased when feeding of the machine tool is blocked, the torsion clutch is released, the machine tool maintains a harmless clamping force, a motor is prevented from being locked or burnt down, and reverse rotation and retreating of the motor are controlled in match with a control circuit. The device is a mechanical anti-locking device, and has the advantages of simple structure, low manufacturing cost, low failure rate, safety and reliability.