The invention provides a composite building material and an intelligent temperature control system. The composite wall body prepared from the composite building material comprises an electric heating layer, an energy storage layer and a heat preservation layer which are attached to one another, wherein the energy storage layer is prepared from cement, fine aggregate, graphite and a phase change material. The invention further provides an intelligent temperature control system, which comprises a temperature sensor, a power supply, a PID controller and the composite wall body, wherein the power supply is used for heating the electric heating layer in the composite wall body, the temperature sensor is used for monitoring the temperature change of the composite wall body, and the PID controller is used for controlling the power supply and processing data collected by the temperature sensor. According to the composite wall body, heat conduction and electric conductivity of graphite are fully exerted, electric energy supplied by the outside can be transferred into heat for heating, heat energy can be stored when the environment temperature is high, heat energy can be automatically released when the environment temperature is lowered, and the composite wall body has the advantages of being long in heating continuity and low in energy consumption.