The invention discloses a hybrid electric vehicle energy-saving predictive control method based on platoons. The method includes acquiring real-time traffic information of the own vehicle and front vehicle from a global positioning system and an intelligent traffic system as system input; establishing a hybrid electric vehicle mathematical model serving as future vehicle state predication basis; defining the hybrid electric vehicle platoon optimal control problem, and providing a function equation to figure out an optimal control value; feeding back the optimal control in real time, figuring out the optimal control value, after the safe distance is met, acquiring the information to adjust and optimize hybrid electric vehicle energy flowing online according to the global positioning system, a radar, the intelligent traffic system and a vehicle communication system, and acquiring the optimal performance of the hybrid electric vehicles. A planetary gear mechanism serves as an electronic variable transmission, an engine is in the optimal operating point constantly, the front vehicle driving state is predicated through the road traffic information, the hybrid electric vehicle energy flowing is adjusted online, the purpose of energy saving and emission reduction is achieved; the method is different from a traditional fixed time headway control method, and a novel way is provided for improving the performance of a central controller of a hybrid electric vehicle management system.