With the rapid development of optoelectronic technology, the application of space communication technology becomes wider. The performances of low-loss, anti-interference and high signal to noise ratio are required by laser communication systems. Anti-stray light interference filter film is made to meet the requirements of multi-channel signal transmission and reception. According to optical thin film theory, the double band high pass filter film satisfying simultaneously 808 nm and 1 064 nm is designed. Using ion-assisted deposited technology and film thickness error analysis during quartz crystal coating monitoring process, a mathematical model about film fit quantitative calculation is built. And the model is used to fabricate double band-pass filter. The film system designed through the model can be fabricated easily and meets actual application requirements.