A new integrated system which combines the coal-derived synthetic natural gas system with off-grid wind power is presented in this paper. In this system, wind power is used to electrolyze water to produce H2 and O2. The O2 is fed to the gasifier as gasification agent. The H2 is mixed with the syngas to adjust the H2/CO ratio for methane synthesis. In comparison with the conventional system, the integrated system makes use of off-grid wind power, avoiding impacts to grids and reduces the watergas shift process, which brings both advantages in the utilization of all raw materials and mitigation of CO2 emission. Taking a coal-derived synthetic natural gas project and a typical wind power farm in Inner Mongolia for demonstration, the integrated system was designed and analyzed for technical feasibility. The integration improves energy efficiency and decreases CO2 emission. One key issue is the scale and proportion of H2 from water electrolysis by wind power and the instability of wind power should not interrupt the chemical process. Results show that 90% of H2 needed to adjust the H2/CO ratio should be produced by the conventional process and another 10% of H2 should be generated from water electrolysis.