The invention belongs to the field of autonomous navigation, guidance and control of spacecrafts, and provides a star pattern recognition method based on plane triangles. The method comprises the following steps: firstly, establishing a navigation star database, specifically, constructing characteristic plane triangles, carrying out principal component analysis on all matrixes formed by the characteristic plane triangles, calculating projection values of the characteristic plane triangles in the direction of intrinsic axis, and sequencing the projection values; then, constructing observation plane triangles; and finally, searching for characteristic triangles matched with the observation plane triangles in the navigation star database by means of a K-vector searching method, and getting rid of redundancy match by means of least square errors to determine the final matched triangles. The star pattern recognition method based on the plane triangles provided by the invention overcomes the defects that the poor noise robustness is poor, more redundancy matches exist and the identification rate is low in conventional triangle identifying methods. The retrieval of the navigation star database is accelerated, the redundancy matches are eliminated, the recognition rate is increased, and the noise robustness is good.