Mature long distance theory of vibration energy collision metastasis was applied to massive molecular system. A collision theory of ²³⁵UF₆ and ²³⁸UF₆ isotope molecules was established with quasiclassical method. v₃ vibration energy near resonant energy transfer process of ²³⁵UF₆ and ²³⁸UF₆ isotope molecules was studied. Resonance functions of energy difference,resonance transfer probability and resonance transfer rate as functions of temperature were obtained. It shows that they decrease with increase of temperature. Collision molecular translation decreases resonance transition probability and rate. It provides a theoretical basis for controlling selective loss processes caused by vibration-vibration transfer. It provides a reference for separation of uranium isotopes.