Abstract: With respect to the trace design of spatial directional well which is not solved yet in the field of coalbed methane exploration and development,the inclined plane design method of branch well is presented,Using this method,the design of spatial directional well could be simplified as a design of directional well in inclined plane,while the latter could use the design method of directional well in vertical plane.Therefore,this method not only solves the trace design of spatial directional well,but also is simple and flexible in design.