Based on the trundle bearing mechanisms adopted by China's space station for solar-oriented driving mechanisms，an improved conical roller scheme is proposed.The contact forms of the roller-rail kinematic pairs are focused，the phenomenon of "sliding in rolling" existed in the cylindrical shape roller scheme is analyzed，and the design of roller structure is optimized.In order to verify the correctness，engineering feasibility，and improvement effectiveness of the improved scheme，the roll-slip ratio is calculated，the effects of factors such as machining precision，assembly deviation，and space temperature environment on the roll-slip ratio are assessed，and the effects of the improved scheme on the mechanical interface and load conditions are analyzed.In addition，vacuum life tests are carried out.The results suggest that the improved scheme can realize pure rolling of roller-rail kinematic pairs in theory，has good tolerance and adaptability to machining precision，assembly deviation，and space temperature environment，has no influence on the mechanical interface and load conditions，and can effectively improve the contact status of the roller-rail kinematic pairs and prolong the life，meeting the application requirements.