The electrode is one of the most important components of the pulsed plasma thruster(PPT), which has great influence on PPT performance. In view of this, the upper limitation of PPT efficiency theoretically was analyzed, and the results showed that the upper limitation of PPT efficiency increases by increasing the flare angle or decreasing the end width of electrodes. And then the impulse bit and the mass bit of different PPTs were measured by varying the flare angle and the end width of electrodes. The experimental results indicated that the flare angle has different effects on mass bit of PPTs for different electrode shapes; effects of flare angle on impulse bit are similar to the effects of flare angle on mass bit for corresponding electrode; the specific impulse increases firstly and then decreases with the increase of flare angle; the influence of electrode shape on the performance of PPTs is different at different flare angles.