The present invention relates to a computing unloading method and system for energy efficiency optimization in an in-vehicle edge computing network. The method comprises: calculating an energy efficiency cost (EEC) of local computing; calculating an EEC of mobile edge computing; determining an optimal unloading policy on the basis of the EEC of the local computing and the EEC of the mobile edge computing; determining an optimal CPU frequency and an optimal transmission power of a vehicle on the basis of the optimal unloading policy; and determining an optimal transmission time of the vehicle on the basis of the optimal CPU frequency and optimal transmission power of the vehicle. The foregoing method of the present invention can improve computing unloading efficiency.