Disclosed is an efficient thermal energy power apparatus. A nozzle is arranged on a cylinder head of an internal combustion engine. The nozzle is connected to a pressure pump through a pipe. The pressure pump is connected to a liquid storage tank through a pipe. The liquid storage tank is connected to a cooler through a pipe, and the cooler is connected to an exhaust passage through a pipe. The advantages of the present invention are: a working stroke enables the temperature of a cylinder block to be lowered, and the compression ratio is high; due to being filtered by the cooler and the liquid storage tank, discharged exhaust gas is more environmentally friendly than that of existing engines.