Stray light can seriously affect the imaging quality of star sensor optical systems. Existing methods for suppressing stray light often use baffle，which have limited ability to suppress small angle stray light and are relatively large in size. A method based on fiber optic panels is proposed to suppress stray light inside and outside the field of view in response to the above issues. Three systems are analyzed by using simulation software：a system with only a baffle，a system with only a fiber optic panel in front of the detector，and a system combining the fiber optic panel in front of the detector and the baffle. The point source transmittance of the three systems is compared and studied at different field angles. It is verified that the suppression ability of fiber optic panels on stray light at small angles（10°~20°）is superior to that of baffles. Under high angle incident light，the addition of fiber optic panels can effectively suppress stray light. Under the condition of a field of view angle of 25°，the point source transmittance decreases to below 3.8×10^-5. Innovatively proposing the use of fiber optic panels instead of traditional baffles to suppress stray light in the system has important engineering significance for promoting the miniaturization of star sensor technology.