There has been a difficult problem to improve the drilling rate in West Sichuan Basin for a long time. In addition, by use of the ZKZ-1 drillability multi-detector, the research has found that the rock has so high durometer level and abrasion resistance index that it hard to drill. Different drilling methods have different rock drillability value under peripheral pressure. Compare with liquid overbalance drilling, gas drilling can improve the rock drillability value 2 to 5 point. The research can give a direction to improve drilling rate in West Sichuan Basin.