Using ground source heat pump for electric heating brings more social and economic benefits than other heating systems. To improve the energy efficiency of ground source heat pump system, stochastic operational optimal strategy for ground source heat pump system under TOU price is put forward. A method for calculating the thermal load of users is proposed. On this basis, the stochastic operational optimal model of ground source heat pump system is established according to the principle of Chance-Constrained Programming (CCP), which aims to minimize electricity consumption and maximize the thermal comfort. The improved PSO algorithm is used to resolve the model to obtain the optimal control strategy of ground source heat pump system and the load distributive strategy of heat pump units. The analysis of example, a campus heating building heating system, shows that the model and the control strategy proposed in this paper can improve the energy efficiency of electric heating system on campus and lower the cost of electricity consumption without reducing the thermal comfort. This work is supported by National Natural Science Foundation of China (No. U1766203), National Key Research and Development Program of China (No. 2016YFB0901100), and Science and Technology Project of State Grid Corporation of China “Supply and Demand Friendly Interactive System between Urban Customer and Power Grid”.