The invention relates to an adjustment method for first full charge of a boiler, and in particular relates to an adjustment method for first full charge of a circulating fluidized bed boiler burning high-calorific-value bituminous coal, belonging to the field of research on operation modes of a power station boiler. The method comprises the following steps: controlling primary air, secondary air, return feeder fluidized air, external bed fluidized air, material bed differential pressure, fuel ignition and coal input of the circulating fluidized bed boiler according to the design requirements; then adjusting the particle diameter of a starting bed material and coal fuel, changing the input strategy of limestone, and gradually inputting into the external bed of the circulating fluidized bed boiler. According to the adjustment method, the first full charge and stable operation of the circulating fluidized bed boiler burning the high-calorific-value bituminous coal with the external bed can be realized. According to the adjustment method for the first full charge of the circulating fluidized bed boiler burning the high-calorific-value bituminous coal, the blank in the technical field at present is filled, and a precious theoretical reference is provided for design, debugging and operation of the circulating fluidized bed boiler burning the high-calorific-value bituminous coal.