In the hydraulic drive machines, the key to good power, acceleration and economy is the proper and rational matching of power source with the hydraulic torque converter. The previous common practice is the matching of diesel engine with the conventional hydraulic torque converter (unadjustable) . This paper covers the matching of caged three-phase asynchronous motor with the adjustable hydraulic torque converter whose guide wheel buckets are rotatable. This matching is novel and unique. The same features of operation for the motor and adjustable hydraulic torque converter, the matching method, the functional relation in matching and the optimal matching etc. are described. The approach to these problems will undoubtedly contribute to bringing the China's hydraulic drive technology to a new level.