The invention relates to the technical field of steel tube surface treatment, in particular to a steel tube inner surface pickling device. The steel tube inner surface pickling device comprises a tankbody. Multiple support pillars are arranged at the bottom of the tank body in an equally-spaced manner. The tank body is internally provided with a partition plate, and one end and two sides of the partition plate are connected with the inner wall of the tank body in a sealed manner. A collection mechanism is arranged at the other end of the partition plate. Mounting frames are symmetrically arranged above the partition plate. A support is arranged in each mounting frame and provided with a rotating shaft. Multiple vanes are arranged at one end of each rotating shaft, and a transmission mechanism is connected to the other end of each rotating shaft. The end, far away from the collection mechanism, of the tank body is provided with a shell. A water pump is arranged inside the shell. A water inlet and a water outlet of the water pump each penetrate one side of the tank body. The water inlet of the water pump is formed above the partition plate, and the water outlet of the water pump isformed below the partition plate. The device is easy to operate and high in pickling speed; meanwhile, stains on the inner surface of a steel tube can be removed easily in the pickling process; and work efficiency is improved, and meanwhile, the pickling effect is improved.