As the large hole taper and large relative aperture error and other problems exist with laser drilling on Al2O3 ceramic, a technology called low-pressure water jet assisted laser drilling of Al2O3 ceramic has been proposed. Through the comparative analysis, it mainly studied the rules of speed of the water jet on the impact of quality of Al2O3 ceramic using low-pressure water jet assisted laser drilling, compared with the direct laser drilling. Experiments proved that, taking advantage of the erosion and cooling of water jet, the composite drilling can greatly reduce the hole taper and relative aperture error, also can reduce molten slags accumulating on material surface and inwall of Al2O3 ceramic, thus improving and rising the quality of drilling on Al2O3 ceramic.