Abstract: Recent years have witnessed the development and commercialization of power-to-gas（PtG）technology,which has made possible the interconnection within a combined multi-energy system.However,innovative as PtG is in terms of consumption,storage and transportation,its popularization is way ahead.This is because of the technical bottleneck of installed capacity,limited availability,high capital cost and mediocre energy conversion efficiency of current PtG techniques.Given this background,the possible application of PtG technology in multi-energy systems abroad is discussed,and the cost and benefit of PtG plants are analyzed for several specified operation scenarios.Through numerical simulations with real world data for several simplified and ideal test scenarios,it is concluded that the current PtG technological development level is generally economically inefficient based on the present levels of transforming efficiency,cost and capacity.In certain cases,however,the PtG plants may make profits and contribute to efficient operation of the multi-energy systems through reasonable operation strategies.As the capital and operation cost of PtG plants are believed to decrease significantly in the forthcoming years,the PtG technology will be able to demonstrate its economic feasibility through cooperation with natural gas fired power plants,and participation in ancillary service provision.