Abstract: The United States is technically advanced in coal bed methane drilling.This paper focuses on drilling and completion technologies in Western Basin of America,and it points out that the essential conditions for open hole cavity completion in the coal bed formation are as follows:high permeability,fragile coal bed rock and high pressure in formation.The technique of open hole cavity completion and procedures of cavity are described in detail,while the hydraulic fracturing in cased well is also presented and evaluated.