This paper proposed a position compensation method for brushless DC motors with trapezodial back-EMFs. The conventional compensation method of Hall sensors is very complex because of its moving hall sensors on motor body .In this paper, the bus voltage and bus current were used to obtain the commutation time of the BLDC motor, and the optimal advance angle of Hall sensors was determined to achieve the purpose of correcting the Hall position. Finally, the simulation results based on BLDCM with three Hall sensors in the three-phase two-conduction mode effectively and reasonably verify that the proposed methods can modify deviation angle of Hall sensors, make the phase current stable and run up to normal operation mode through the Matlab simulation platform,which validates the feasibility and effectiveness of the proposed strategies.