The utility model provides a reaction chute of a nickel electrolyte purification system. The reaction chute comprises a chute main pipe and a supporting column, wherein the chute main pipe is connected with a plurality of pairs of liquid inlet branch pipes and liquid outlet branch pipes; an instrument opening is formed in each liquid inlet branch pipe, and is connected with a flange plate; a detecting instrument is fixed at the center hole part of the flange plate, and the gap between the detecting instrument and the flange plate forms seal by virtue of a sealing material. The reaction chute disclosed by the utility model has better sealing performance than a conventional square chute by adopting the tubular structure; the flange plate is arranged on the instrument opening, so that the gap between the detecting instrument and the instrument opening is reduced, the sealing performance of the reaction chute of the nickel electrolyte purification system is further improved, the phenomenon of running, popping, dripping and leaking of solutions is eliminated, the phenomenon of environment pollution caused by acid mist and chlorine is solved, the chlorine utilization rate is improved, and the production cost is reduced.