Abstract: In order to study the feasibility and effect of fabrication of metal films with high reflectivity based on near infrared nanosecond pulsed laser, high reflectivity aluminium films were fabricated by nanosecond pulsed laser. Under the conditions of different laser spot sizes and different laser energy, the change of ablation morphology on the surface of aluminium film was measured. The results show that, even if surface reflectivity of aluminium film is as high as 96%, the aluminum film can still be processed by laser. The ablation pattern of defocusing (energy density less than 1000J/mm²) on the surface of aluminium film by high power laser is more regular than that of focusing (energy density greater than 2000J/mm²) on the surface of aluminium film by low power laser. The relevant experimental results can play a guiding role in the selection of laser parameters in laser processing of high reflectivity material.