Tunable optical filter and optical channel monitoring module

The invention discloses a tunable optical filter and an optical channel monitoring module, the tunable optical filter comprises an optical fiber port, a collimating lens, a cascade diffraction grating and a reflector which are arranged along an optical path, the optical fiber port comprises at least one path of input port and output port, the tunable optical filter further comprises a miniature transmission mechanism, and the miniature transmission mechanism is connected with the collimating lens and the cascade diffraction grating. The micro transmission mechanism is used for driving the cascade diffraction grating or the reflecting mirror to deflect, an optical signal sequentially passes through the input port and the collimating lens and then enters the cascade diffraction grating to be dispersed into diffracted light with different diffraction angles, the diffracted light enters the reflecting mirror, and the diffracted light enters the reflecting mirror. The reflector reflects diffracted light in a speci