This paper aims to introduce the gas-phase anti-rust thermal shrinkage packaging technology, and apply this technology to solve the rust problem of large-scale nuclear power metal equipment in the three-year storage process. The combination preservation technique with the gas phase antirust thermal shrink film as the core is used for three-year storage and rust prevention of large nuclear power equipment, and the effect of the gas-phase anti-rust thermal shrinkage packaging technology in the field application is evaluated. Through the field application effect verification, the nuclear power equipment that adopts the gas-phase anti-rust thermal shrinkage packaging technology for three-year combined sealing has not been rusted, the surface of nuclear metal equipment and three years ago have no obvious difference, clean as new, and the antirust effect is excellent. Gas-phase anti-rust thermal shrinkage packaging technology is an effective method to achieve three-year sealing and rust prevention of large nuclear power metal equipment in the warehouse, and the operation process is simple and the antirust material is easy to remove.