With the aim to investigate the influences of blade number on the self-starting performance of vertical axis wind turbine with self-adapting wind speed (VAWT-SWS), a prototype which could change the number of blades (2,3,4) was designed. Through the wind tunnel experiment the static torque coefficient curve with azimuth angle at a wind speed of 3m/s was obtained, and compared experiments were done on Darrieus straight-bladed wind turbine with the same parameters. Then the load of VAWT-SWS was released, and rotation speed curve of VAWT-SWS changing with time at 3m/s was gotten. The experimental results showed that the self-starting performance of VAWT-SWS was superior to that of Darrieus straight-bladed wind turbine; the increase of blade number could improve the static self-starting performance of VAWT-SWS, but degraded the dynamic self-starting performance.