The Ca+CH3I→CaI+CH3 reaction system has been studied with the quasi-classical trajectory method on the extended Lond-Eyring-Polanyi-Sato(LEPS) potential energy surface. At collision energy Ecol=10.78 kJ/mol, the calculated results show that the CaI vibrational population peaks are located at v=2. The calculated cross section decreases slowly with the collision energy increasing. The angle product distributions tend toward backward scattering. The calculated (P2(J^1·K)) values deviate slightly from-0.5 and decrease with increasing collision energy. The Quasiclassical trajectory calculation(QCT) results are in reasonable agreement with experimental data. Moreover, the dynamics of the reaction has been discussed.