Abstract: The main form of ground source heat pump is rock-soil source heat pump system. To find out the causes for the poor operation effect of the system when applied in karst area, the heat transfer test and engineering research are conducted. It is considered that the unfavorable formation lithology and hydrogeological conditions may restrict the sustainable development and utilization of the system to some extent, and the problems existing in the air pressure down-the-hole(DTH) hammer technology and construction may also cause abnormal running of the system. Thus, the paper put forwards some suggestions and countermeasures on strengthening basic geological and hydrogeological survey, geophysical prospecting, drilling technology promotion and process management.