To measure the damage threshold of multispectral filter induced by femtosecond laser, the laser damage threshold of front film of the multispectral filter was experimentally studied by a Ti∶sapphire femtosecond pulsed laser (800nm, 50fs), and the damage morphology of the front film of the filter was observed by a microscope. The results show that the damage thresholds of the front film under different pulse irradiation times (1, 2, 5, and 10) are 1.68J/cm2, 1.56J/cm2, 1.44J/cm2, and 1.42J/cm2, respectively. The damage threshold decreases with an increase in the pulse irradiation number. The repeated laser radiation will form a cumulative effect on the film. Because the width of the femtosecond laser is very short, the conduction band electrons in the film are produced by multiphoton ionization and quickly absorb the laser energy. When the electron energy is greater than the bandgap energy of the material, it will collide with the valence band electrons to produce another electron. A large number of free electrons are generated, resulting in film damage. Under the 1-on-1 and 2-on-1 test methods, the morphology of the damaged area of the front film becomes more apparent and regular with the increase of femtosecond laser fluence, and a clear layered structure gradually appears. The phenomenon is due to the different distribution of the interference field in the front film. This study provides a reference for the damage effect of multispectral filter film under femtosecond laser.