To address the concerns about the range anxiety and low energy recovery efficiency of electric vehicles and hydrogen fuel cell-powered commercial vehicles, this paper, based on the downhill sliding characteristics of the vehicle and the current operating status of the hydrogen fuel cell stack, proposes an energy recovery control method based on Predictive Cruise Control (PCC). This method relies on intelligent connected products to obtain information such as the slope and length of the road ahead, and transmits it through the Advanced Driver Assistance Systems Interface Specifications (ADASIS) v2 protocol to the Vehicle Control Unit (VCU). The VCU then adjusts the speed entering and exiting the slope based on the vehicle's operating status and simultaneously optimizes the power of the hydrogen fuel cell stack, making full use of inertia to climb the slope and reduce energy consumption. The multi-steep slope section test in Mohe verified that this method can significantly improve energy recovery efficiency and reduce the vehicle's energy consumption, providing technical support for the improvement of the range of electric and hydrogen fuel cell-powered commercial vehicles.