According to the requirements of Light Emitting Diodes (LEDs) for consistency and reliability, when they were taken as a light source in spaceborne calibration, a screening experiment scheme using multiple LEDs as spaceborne calibration light source was proposed, and a screening device was developed. In order to test the working stability and the consistency of luminescence for the LEDs, this device could monitor and measure the luminous status of multiple LEDs automatically at the same time. Using this device, 72 white LEDs which were randomly selected were tested. According to the analysis and calculation of the experimental data, the result shows that the change of the relative intensity is about 1.5% after those white LEDs are lighting for 900 h. Finally, 10 desirable LEDs are screened depending on the requirements of the light source.