Nanosecond laser drilling micro-holes are widely used in industry. However, the existence of recasting layer reduces the service performance and life of micropores. How to reduce recasting layer thickness and improve hole wall finish remains to be further studied. In this paper, the Ni-base superalloy is taken as the research object. By comparing with the ultrasonic assisted nanosecond laser drilling, the influence of ultrasonic assisted water on the micropore geometry, the roughness of the hole wall and the recasting layer is analyzed. The results show that for the through holes made by nanosecond laser, the ultrasonic assisted method can reduce the roundness error of the outlet hole, increase the taper, reduce the roughness of the hole wall, reduce the recasting layer of the hole wall, and improve the quality of the micro-hole. However, under experimental conditions, water-based ultrasonic assistance has little influence on the geometrical size and hole wall morphology of the blind hole. It can be seen that the quality of nanosecond laser hole making can be improved to a certain extent with the help of ultrasound.