The invention relates to a state-of-charge (SOC) control method of a hybrid electric vehicle; the SOC of the battery is divided into different sections; whether power generation/driving are allowed is controlled respectively for different working conditions in different sections; corresponding power generation/driving torque is calculated; the division of different SOC sections can better realize all functions of the hybrid electric vehicle in specific sections and under certain conditions; all power generation/driving functions are permitted in the A section; only regeneration braking is allowed in the B section, and an auxiliary driving to improve the engine efficiency is provided in the B section. The control method can well stable the battery SOC in the preset section, find more reasonable power generation and auxiliary driving chances during vehicle traveling, ensure the vehicle to provide auxiliary driving function stably, improve the performance of the vehicle and reduce the exhaustion.