Cyclone desanding device

The invention discloses a rotational flow desanding device, relates to the technical field of sand washing equipment, and aims to solve the problems that an impeller is easily damaged due to collision of high-hardness sand and stones and a valve at the bottom of the desanding tank is easily clamped by the sand and stones and cannot be closed in the process that the impeller is used for generating rotational flow in an existing large rotational flow desanding tank. According to the technical scheme, the device comprises a tank body, a rotational flow barrel and a rack, a sewage pipeline is tangent to the circumference of the side wall of the tank body, and sewage injected into the pipeline forms first-stage tangent plane rotational flow; a second-stage rotational flow assembly arranged on the side wall of the rotational flow barrel pumps water and pressurizes the water, and the water is injected into the rotational flow barrel to form a second-stage pressurized rotational flow; the three-stage rotational flow