Abstract: The flux leakage controllable permanent magnet (FLCPM) motor is a new type of flux-controlled permanent magnet motor with low speed, high torque, and wide speed range characteristics. It has a potential wide application prospect in the field of multiple operating condition electric drive. In order to solve the problems of mismatching of control system parameters and low efficiency caused by the change of flux and inductance of this kind of motor with current, a control strategy of maximum torque per ampere under parameters variable is proposed in this paper. According to the operation principle of the FLCPM motor, the mapping relationship between flux leakage and operating conditions is established, and the medium and high load areas with obvious parameters change are divided into three typical operating conditions. On this basis, a nonlinear piecewise variable parameter derivative term solution method is proposed, and the equation for solving the maximum torque per ampere of FLCPM motor under varying working conditions is derived to achieve the optimal d/q axis current distribution of this type of FLCPM motor, thereby improving the efficiency of FLCPM motor under multiple operating conditions. Finally, the effectiveness of the proposed theory and control strategy is verified by experiments.