Abstract: Based on Solar explorer,A celestial navigation method usingthe angle relative to Solar rotation axis is proposed for Solar explorers. Measuring the speed difference between two sets of mutually perpendicular points on the edge of the Solar surface by the spectrometers, a mathematical model for speed difference and the angle is established and the angle is used as a new measurement to provide position information of the explorer. The simulation results show that the position error of the proposed methodis reduced by 17. 4% compared with the traditional method using the sun line-of-sight vector measurement. In addition,the influence of the accuracy of speed sensor,the filter period as well as the orbit inclination are analyzed. It will provide a new way for autonomous navigation of deep space exploration.