In this paper，taking an annual output of 1×109 m3 coal to substitute natural gas(SNG) as an example，Shell coal gasification technology was used to produce synthesis gas. The equipment investment of air separation system（ASU），water gas shift system（WGS），wind power plant（WP） and electrolyzed water system（EWS） was compared between traditional coal-to-SNG and wind/coal SNG. The oxygen consumption，water steam consumption，electricity consumption and CO2 emission were also analyzed. Results show that although the investment of WP and EWS replacing the ASU and WGS is huge， its average annual operating cost（equipment investment，raw materials，power consumption） is lower，and CO2 emission is only 1.3 % of the traditional coal-to-SNG technology. This paper provides a reference for the development of coal-to-SNG industry.