Abstract: This study tested the performance of an electrically heated catalyst（EHC） under different heating modes on a 2 L gasoline engine with a rated power of 100 kW, designed for range-extended hybrid commercial vehicles. It investigated preheating by activating the electric heater before engine cold start and injecting compressed air at different flow rates. Simultaneously, a 150-second cold start segment was established based on typical engine operating conditions and cold start characteristics. The study examined the effects of preheating, post-heating, and hybrid heating modes on THC, CO, and NOx emissions during the cold start segment. Results indicate that considering the TWC carrier heating characteristics, a 31 kg/h air flow rate is optimal for preheating. The hybrid heating mode demonstrates superior pollutant reduction performance during cold start conditions.