In order to study the structure stability of fine support components made of Carbon Fiber Reinforced Polymer (CFRP) in a large-aperture space optical remote sensor,a CFRP joint cylinder between primary mirror and second mirror was designed and manufactured.The maximum deflection was calculated in the light of the angle change between primary mirror and second mirror,and the mechanical model of the joint cylinder was established according to actual load.The axial elastic modulus based on the model was calculated and the an appropriate layer sequence CFRP was determined by composite laminate theory.Then,the angle between the two mirrors and the modal distribution of support structure were calculated based on software ANSYS.Finally,the structure stability was validated by the crescent mechanic test and optical measurement method.The results show that the angle displacement between primary mirror and second mirror is less than 10″,the first-order natural frequency of CFRP support component is greater than 75 Hz.CFRP support has better structure stability,which satisfies the requirement of general technologic index.