The invention discloses an acetic acid reaction kettle fluid mixing system, which comprises a reaction kettle and a fluid stirring device, wherein the fluid stirring device comprises at least two spraying nozzles, a pump and a heat exchanger, the inlet end of the pump is communicated to the middle portion of the reaction kettle, the outlet end of the pump is communicated to the inlet end of the heat exchanger, the fixed pipeline of the spraying nozzle is fixed at the top portion of the reaction kettle, the outlet end of the heat exchanger is communicated to the end portion of the fixed pipeline of the spraying nozzle, the spraying nozzle is arranged near the inner wall of the reaction kettle, and is arranged 200-500 mm below the liquid level of the reaction little, and the included angle between the diameters of the two adjacent spraying nozzles is 45-90 DEG. According to the present invention, the fluid stirring device is arranged so as to change the condition of easy damage on the mechanical stirring shaft seal and the transmission device during the operating, and the dynamic sealing point is eliminated so as to improve the safe and stable operation of the system; and by matchingwith the CO distributor, the CO gas distribution in the reactor is uniform so as to improve the gas-liquid two-phase mixing effect, increase the reaction rate, and optimize the reaction state of thesystem.