Gas-solid ratio control method and system and fluidized bed jet mill

The invention relates to a gas-solid ratio control method and system and a fluidized bed jet mill. The method comprises the steps that the first flow of compressed air entering the fluidized bed jet mill and the weight of materials in the fluidized bed jet mill are obtained; calculating the weight ratio of the first flow to the material in the fluidized bed jet mill to obtain a first gas-solid ratio; calculating a first difference value between the first gas-solid ratio and a first standard gas-solid ratio; judging whether the first difference value meets a first preset difference value standard or not; if the first difference value does not meet the first preset difference value standard, the feeding frequency of the fluidized bed jet mill is adjusted according to the first difference value, so that the difference value between the gas-solid ratio obtained after adjustment and the first standard gas-solid ratio meets the first preset difference value standard; the feeding frequency is the frequency of feedin