Abstract: Nonequilibrium statistical theory is used to establish the statistical theory for helium embrittlement of irradiated metals. From the density distribution function of helium bubbles and the average fracture radius of helium bubbles derived previously, the macroscopic properties of irradiated metals in helium embrittlement fracture are discussed, including the fracture probability and reliability of the metals, swelling, lifetime and fracture strain of the metals. Good agreement between the theoretical results and the experimental data demonstrates the correctness of the proposed theory.