The present invention relates to a mechanically controlled continuously variable automatic transmission, comprises a housing and a torque converting mechanism mounted in the housing, the torque converting mechanism comprising an input part, a rotatable or rotary carrier, at least one eccentric assembly which is rotatablely mounted on the carrier, and an output part, wherein the input part and the carrier can rotate independently with respect to each other, and have respective rotation axes which are collinear. Each of the at least of one eccentric assembly comprises an eccentric mass which is driven to rotate around its rotation axis by the input part, the output part is provided with only one one-way clutch directly connected therewith. The mechanically controlled continuously variable automatic transmission not only can automatically adjust the output speed and moment depending upon the magnitude of load applied thereto so as to well achieve a function of stepless automatic change of the speed, but is also simple in structure, high in transmission efficiency, and long in life time. Furthermore, the transmission can be applied to an operating condition of high rotary speed and can effectively transmit large power and motive power with large torque, so that it can be used in various vehicles and has a wide application range.