The theory of direct torque control (DTC) in permanent magnet synchronous motor (PMSM) was investigated. The effect of zero voltage vectors for the PMSM DTC drives was analyzed. The strategy of selecting zero voltage vector was proposed based on the minimum switching times, and a new switching table with zero voltage vectors was given. Simulation results showed that the PMSM DTC system could work properly using the new table. Switching times of the DTC system using new switching table were decreased by direct torque control nearly 56% compared to conventional switching table, therefore, switching loss was decreased.