Integrated Gasification Combined Cycle power generation technology is recognized as one of the important future development directions of clean power generation. Taking a large-scale IGCC power plant as the research object, the operating strategy of single unit tripping in multi-units was discussed in this paper. Gasification unit and air separation unit shall ramp down and balance with various gas demand in 1–2 minutes after one-unit trips. Duct burners of heat recovery steam generator can be used to produce more steam and increase steam turbines output subsequently. New stabilized power output can be reached within 20 minutes after the tripping.