To solve the problem of voltage waveform distortion of small single phase synchronous generators (SSPSG) when operating with loads, a method of timestepping finite element coupling with circuits is used to model the SSPSG and compute the SSPSG electromagnetic field with different damper winding connection types and using different damper winding materials when carrying rated loads. The voltage harmonics of each condition are compared and the influences of the damper winding analyzed. The results indicate that the SSPSG damper winding can weaken the negative sequence magnetic field in SSPSG, decreasing voltage waveform distortion. The damper winding connection manners play a much more important role than that of winding materials on weakening the negative sequence magnetic field in SSPSG.