Biomass is converted into combustible gas via fluidized bed gasifiers. The hot product gas is transported through insulated pipelines to coal-fired power plants, where it is coupled with pulverized coal boilers using specially developed central-injection biomass gas burners. This technology addresses the challenge of stable combustion at low loads for pulverized coal burners, reduces the minimum load required for oil-free stable combustion, and enhances the flexible peak shaving capability of large-scale thermal power stations. It enables deep flexible peak shaving for coal-fired units while achieving coal savings and emission reductions.