The invention is applicable to the motor control field, and provides a starting method and system for a permanent magnet synchronous motor. On the basis of a static coordinate system and a rotor coordinate system that are frequently used in a mathematic model of the permanent magnet synchronous motor, a starting coordinate system is additionally introduced to enable an open loop run phase of the permanent magnet synchronous motor to be operated in the starting coordinate system; a closed loop run phase is converted from the starting coordinate system into the rotor coordinate system, so that the problem of jumping current and rotor speed when the permanent magnet synchronous motor is in transition from the open loop run phase to the closed loop run phase is solved, and the starting process of the permanent magnet synchronous motor can be smoothly and naturally performed; meanwhile, when the starting parameters and loads of the motor are obviously changed, the starting of the permanent magnet synchronous motor is controlled by the starting method and system provided by the invention without affecting the smoothness of the starting of the permanent magnet synchronous motor; and in addition, the starting method is high in robustness and applicable to wide promotion and use.