The traditional method of fast selection satellite based on elevation is mainly focusing on the research of single point positioning accuracy, and this article study the influence of satellite elevation on position accuracy directed on differential positioning. To verify whether the introduction of low elevation satellites by the differential station affects the accuracy of the self-closing-loop pseudo-range differential positioning results on the three frequency points of the differential station reference receiver, we filter out the time index of newly added low elevation satellite(defining elevation angles below 12 degrees as low elevation angles), then according to this time index, we statistic the self-closing-loop differential positioning results for the three frequency points(GPSL1、BDB1、BDB3) of the reference receiver in sequence, and compare and analyze the pseudo-range differential positioning results of the selected time period based on the elevation angle of the rapid star selection. The experimental results show that differential positioning based on the elevation angle of the rapid star selection can significantly improve the positioning accuracy.