Abstract: The purpose of this paper is researching about high-power and high beam quality laser as well as the experiment of the high-quality micro-hole.The theoretical analysis of the plane-convex unstable laser resonator structure is introduced.The parameter about resonator is analyzed.The high-power and high beam quality pulsed Nd: YAG laser with the plane-convex unstable laser resonator pumped by lamp is designed.The output of laser pulse energy is 500mJ;the peak power is 5MW.The beam parameter product(BPP) is superior to 4.2mm·mrad. Using the laser for drilling processing experiment on metal(steel material) with different thickness from 0.04mm to 0.07mm and non-metal(ceramics material) with 1mm thickness is achieved.