Abstract: As the coal material for underground pyrolysis and gasification is the primitive coalbed of hundreds even thousands meters below, the ground catalytic approach is hardly used for underground catalytic pyrolysis or gasification. This thesis illustrates the special design for the underground catalytic pyrolysis solution that takes catalytic pyrolysis test on the anthracite from Changji, Xinjiang with Ca(OH)2 catalyst in the horizontal pyrolysis reactor, and obtains chars of before and after catalytic processing, and tests the specific area, XRD and char gasification reactivity of the char. The test results indicates that Ca(OH)2 activates char pyrolysis, increases specific area rapidly and varies the pore size distribution. Moreover, the catalyst speeds the thermal cracking of organic functional groups in the coal, blocks retrogressive reaction of aromatic free radical, suspends order reaction and graphitization of char pyrolysis, and enhances reactivity of the coal char.