This paper studied the diffuser panel used for onboard calibration for satellite optical sensors. In order to investigate it’s stability and the adaptability under spatial environment,a series of environment simulation tests such as vibration and shock,temperature cyclic,vacuum bakeout and UV/VUV were planed and implemented. The diffuser’s optical properties were retentive after tests. The difference of reflectance at 350nm before and after UV/VUV test is within 3%. Analysis shows that some degradation of optical properties under UV radiation has been linked to degradation of contaminants,which can be prevented by improvement of production protocol and environment control. At the same time,the diffuser panel goes though space level mechanical environment tests. So,the space stability of the diffuser panel used for onboard calibration can satisfy the spatial application demand.