The invention discloses an efficient direct-expansion solar heat pump and water source heat pump coupled heat supplying system. The system is characterized in that the angle of a solar heat collector is adjusted in real time through a full-automatic solar tracking device, therefore, sunlight vertically irradiates the solar heat collector, and maximum solar radiation energy is achieved; by arranging a phase change heat storage device on a direct-expansion solar heat pump system, the evaporating temperature of a refrigerating agent is kept within a certain range, and then influences of changes of the solar radiation intensity to the system stability are greatly reduced; solar energy is stored through a heat storage water tank, intermediate water is preheated through the heat storage water tank, therefore, heat obtained through the direct-expansion solar heat pump system is effectively transmitted to a user, and then effective coupling of a solar heat collection and heat storage technology and a water source heat pump is completed. The efficient direct-expansion solar heat pump and water source heat pump coupled heat supplying system has the advantages that the problems of intermittency and unstability of solar energy sources are effectively solved, it is guaranteed that the system can stably supply energy, the system performance is significantly improved, and high efficiency and environmental friendliness are achieved.