To further reduce the noise, raises the efficiency of voltage, the voltage space vector SVPWM technology be adopted to design inverter air-conditioner. By the basic standard of motor’s ideal magnetic flux with three-phase symmetrical sine wave voltage power supply is considered, use the actual magnetic flux with the inverter different switch pattern to approach the base director circle magnetic flux, compares the results to decide which time the inverter’s switches open and pass, forms the PWM waveforms. And regards the inverter and the electrical motor as a whole to process, It has the merit of model to be simple, the torque pulsation be small, the noise be low, voltage use factor higher and so on. The theoretical analysis and the experimental result indicated that this method can definitely satisfy the inverter air-conditioner designing requirements.