The invention discloses a cooling water pump belt pulley assembly for an automobile engine. The cooling water pump belt pulley assembly comprises a belt pulley consisting of an internal belt pulley and an outer belt pulley and is characterized in that: the inner hole of the internal belt pulley is provided with a double row ball bearing; the right side of an excircle of the internal belt pulley is connected with an engagement block which is adhered with a locking piece; a return spring is arranged in the engagement block; the middle left part of a shaft connection bearing of a cooling water pump is matched with a water pump flange plate; the excircle of the water pump flange plate is in interference fit with a flange connection disk; a coil is wound on the flange connection disk and is connected with a finished automobile power supply and an electric control unit (ECU); the left end of the shaft connection bearing of the cooling water pump is in interference fit with an inner ring of the double row ball bearing; and the engagement block of the right side of the internal belt pulley corresponds to the coil on the flange connection disk. By the cooling water pump belt pulley assembly, whether the water pump works is adjusted timely according to the different running working conditions and the different running environments of an engine, the running temperature of the engine is greatly improved, and more reasonable combustion is realized, so that the oil consumption and discharge of a finished automobile is greatly reduced.