An efficient temperature stratification heat exchange energy storage water tank with internally arranged phase change thermal storage materials comprises an energy storage tank body, layered heat exchange coils, inlet and outlet baffle plates and thermal storage balls, wherein the phase change thermal storage materials are arranged inside the thermal storage balls, a gas exhaust valve and a blow-down valve are arranged on the energy storage tank body, a water inlet of a heat exchanger, an inlet of a hot water pipe coming from a heat collector, and hot water outlets heading to users are located on the upper portion of the energy storage tank body, and a water outlet of the heat exchanger, low-temperature water inlets from the users, and low-temperature water outlets heading to the heat collector are located on the lower portion of the energy storage tank body. The efficient temperature stratification heat exchange energy storage water tank with the internally arranged phase change thermal storage materials is characterized in that the heat exchange coils are arranged in three layers inside the energy storage tank body and divide the energy storage tank body into three layers, the three layers are a high temperature region, a medium temperature region and a low temperature region sequentially from top to bottom, the phase change thermal storage materials are encapsulated inside the small thermal storage balls, a certain space is left in each thermal storage ball for size changes, when heat is stored, the phase change thermal storage materials turn into the liquid phase from the solid phase, and when the heat is discharged, the phase change thermal storage materials change reversely. All the inlets and the outlets directly connected with the energy storage tank body are provided with the inlet and outlet baffle plates.