Currently, numerous cities are adopting electric buses (EBs) to replace fuel-powered buses. However, due to higher electricity prices during the daytime, transit operators face higher charging costs when EBs are charged during daytime hours. This paper proposes a hybrid “Energy Storage System-Power Grid (ESS-PG)” power supply strategy, wherein the ESS is deployed at EB terminals. This system is charged using the PG during off-peak hours at night with lower electricity prices. The stored energy is then used to charge EBs during daytime operations, thereby reducing the charging costs for transit operators. To determine the optimal ESS capacity, EB battery capacity, EB fleet size, EB trip and charging schedules within the hybrid power supply strategy, we develop a collaborative optimization model that integrates the full lifecycle system resource configuration and daily operational scheduling schemes for the EB route. The model is solved using a combination of branch-and-bound and an improved two-stage genetic algorithm. The effectiveness of the proposed method is validated using a real-world EB route. Results indicate that, in comparison to the unitary PG energy supply strategy, the proposed strategy can save 21.2 % of operating costs and reduced carbon emissions by 60.2 tons for the EB route.