Disclosed is cylindrical ore washer for hydrometallurgical smelting of laterite nickel ore, comprising a mounting bracket, a screening component, a regulator, and an ore-washing component. The screening component comprises a frame, a cylinder body, a screening cylinder, and a driving component. The cylinder body is rotatably mounted on the frame along an axis in a first direction. The screening cylinder is housed within the cylinder body, with a feed inlet and a discharge outlet located at opposite ends along the first direction, respectively. The screening cylinder is gradually inclined downwards from the feed inlet to the discharge outlet. Multiple screen holes are provided on the cylindrical wall of the screening cylinder, and an inner side wall of the screening cylinder protrudes to form a baffle plate. The baffle plate is inclined relative to the radial direction of the screening cylinder and located at the discharge outlet. The driving component is connected to the cylinder body. The frame is movably mounted on the mounting bracket, allowing adjustable inclination of the screening cylinder. The regulator is connected to the frame. The ore-washing component is set on the frame. This disclosure is capable of impeding the movement of ore towards the discharge outlet, thereby prolonging the residence time of the ore within the screening cylinder and enhancing both the ore-washing efficiency and cleaning effectiveness.