Self-adjusting planetary gear rational mechanism can eliminate the influence of various uncertain errors in mechanism. Therefore ,it's method of self-adjusting designing is attented by machine designer. For seeking a simple, regular, and widely realizing self-adjusting designing way, this article uses approach of the follow text to design no over-constraint and self-adjusting mechanism. First, the article advances the conception of planetary gear structure muster and it's plotting basis, through using for reference the strategy and method of self-adjusting structure groups in planar linkage mechanism. Second, it designs the self-adjusting planetary gear structure muster, through analyzing the constraint and freedom of planetary gear structure muster. Third, it designs the self-adjusting mechanism, through adding aptitude rotational links outside of self-adjusting planetary gear structure muster. This mechanism can realizes the self-adjusting in the interior of muster and self-adapting in the exterior of muster. This designing plan possesses a series of excellence, such as, theoretical, simple, feasible, widely self-adjusting. Consequently, the mechanism can eliminate the working capability influence of various errors.