The paper which was focus on the efficiency-optimization of IPMSM drive system studied the MTPA system and analyzed the drawbacks of the MTPA. Based on the traditional efficiency-optimization algorithm, a novel LMC control strategy was proposed that the effect of copper loss, iron loss and stray loss and the second compensation for parameter variation were fully considered. To met the efficiency-optimization accuracy and engineering realizable, the engineering simplification were done in practical application. The simulation model of system with MATLAB was established, the performance of two kinds control strategy were compared and analyzed, the simulation results demonstrate the feasibility of the control strategy.