The utility model discloses a recovery device of magnetic particles in fluid, which comprises a magnetic particle absorption device and a magnetic particle collection device, wherein the magnetic particle absorption device comprises a set of absorption pipes absorbing magnetic particles on inner walls, a water storage container, and a water discharging container, wherein the top of the water storage container is communicated with the lower ends of the absorption pipes and the bottom of the water discharging container is communicated with the upper ends of the absorption pipes; the top of the water discharging container is provided with an upper clean water inlet and an upper water outlet; the water storage container is provided with a water inlet, a lower clean water inlet and a lower water outlet; the magnetic particle collection device comprises a collector and an electric magnet arranged at the bottom of the collector, the collector is provided with a collector water inlet and a collector water outlet, and the bottom of the water storage container is connected with the collector water inlet of the collector by a pipe. The utility model can realize the separation and the recovery of particles of micrometer and nanometer composite magnetic catalysts from the solution under the condition of solution flowing, and has convenient operation and high recovery efficiency.