Abstract: It can make Pu material stabilize at room temperature to dope a small quantity of metal alloy chemical element, such as Al, Ga, In, and Ce etc., in the Pu material. The collective behavior of helium bubble in the Pu-Ga alloy was simulated under 300 K using molecular dynamics (MD) method and embedded atom multibody potential (MEAM). The Ga content (atom fraction) of Pu-Ga alloy is 0%, 2% and 5% respectively. The trend of helium bubble radius and pressure was achieved with the increase of helium atom number in the Pu-Ga alloy at different Ga contents, and the bulk swell of Pu-Ga crystal due to helium bubbles was revealed. The calculation and analysis can provide reference to understand the internal mechanism of helium bubble in self-irradiation damage in plutonium.