Optical film thickness monitoring system

The utility model discloses an optical film thickness monitoring system. The optical film thickness monitoring system comprises a light source, a light collecting module, an optical film to be detected, a detection module and a processing module, the light source respectively outputs a first optical signal and a second optical signal, and the first optical signal is adjusted by the light collecting module, the optical film to be detected and the detection module in sequence and then outputs a monitoring optical signal to be received by the processing module; after the second optical signal passes through the detection module, a reference optical signal is output and received by the processing module, the processing module calculates the film thickness of the optical film to be measured according to the monitoring optical signal and the reference optical signal, the detection path is shortened, the film monitoring accuracy is ensured, and meanwhile the overall size of the optical film thickness monitoring syst