Taking a novel hybrid-power gas engine heat pump as an example, fuel-consumed rate, fuel-consumed flow, fuel conversion efficiency and life cycle assessment were used to analyze energy-saving effect and natural gas environmental benefits on human health, ecosystem quality and resource consumption through contrast with electric power consumption model. The test results show that the fuel conversion efficiency under different operating conditions of HPGHP is higher than conventional GHP under the same load. Besides, from the total indicator, scores on resource consumption is the highest. Gaseous product is mainly CO2 and other carbon or sulfur oxide gases are discharged in form of negative or water body, which means the use of natural gas effectively control the pollution gas emissions. At last, concept of environmental benefit time was established; the result shows that HPGHP can embody better environmental benefits than gas heat pump when running more than 1778 h.