Ground-source heat pump is a new air-conditioning technology with energy saving and environmental protection. Some issues on the applicability of ground-source heat pump were investigated, such as the techno-economic condition, building load condition and capacity configuration, for its popularization and application in substations. This study puts forward some suggestions on the applicability of ground-source heat pump in terms of the upper limit of initial investment, the lower limit of energy efficiency ratio (EER), the upper limit of investment recovery period, the lower limit of building load and the collocation mode of heat pump unit.