Abstract: According to the influence of each laser parameter on processing and the advantage that a laser can achieve high laser quality nearby the last threshold,AOM Q-switched Nd∶YAG pulsed laser is adopted for microdrilling.As a result,the 15μm microhole in 0.7mm-thick zincification plate steel is obtained,and the ratio of depth and width is over 50,100% drilling rate is acquired.This method can achicve high quality laser microdrilling based on experiment.