Abstract: Clamping multilevel inverter and 2H-bridges cascaded multilevel inverter have complex circuit structure and control,while 3H-bridges cascaded multilevel inverter can overcome the disadvantages.SVPWM control method of five-level inverter is already relized,but if it is used in inverters outputing more levels,then computational complexity would be very large and control would be difficult. While on the base of the control method,through adopting suitable phase-shift angle between space voltage vectors,it is easy to realize SVPWM control of 3H-bridges cascaded multilevel inverter.The paper took 3H-bridges nine-level inverter as an example and adopted Matlab simulation to verify feasibility and correctness of the control method.