The invention discloses a raw material mixing device of a fire extinguishing agent. The raw material mixing device comprises a shell, a top cover, a motor, a feeding opening, a discharging pipe, a discharging cover, a smooth shaft and a rack. The top cover is fixedly arranged at the top of the shell, the feeding opening is fixedly formed in the top cover, the discharging pipe is fixedly arranged at the bottom of the shell, the discharging cover is installed on the discharging pipe in a threaded connection manner, the smooth shaft is vertically arranged in the shell, and an output shaft of the motor is fixedly connected with the upper end of the smooth shaft; an upper spiral stirring blade is fixedly arranged on the upper half portion of the smooth shaft, a lower spiral stirring blade is fixedly arranged on the lower half portion of the smooth shaft, a weighing sensor is fixedly arranged on the upper end face of the rack, and the shell is fixedly arranged on the weighing sensor; and a center processor is arranged on the rack, the weighing sensor is connected with the center processor through a wire, and a displayer is connected with the center processor through a wire. The raw material mixing device has the beneficial effects of being even in material mixing, good in effect and the like.