The invention provides an annular channel air inflow type pneumatic lifting device capable of preventing slurry outage and backflow. The lifting device is connected to a lifting pipeline, an annular air inlet channel is formed in the lifting device and is communicated with the inside of the lifting pipeline, end caps are arranged at the tail ends of the lifting device, and air inlet holes are formed in the end caps. A sliding stopping plate groove is formed in the position, located above the annular air inlet channel, in the lifting pipeline, and a sliding stopping plate is inserted into the sliding stopping plate groove and vertically moves in the sliding stopping plate groove to open or close the annular air inlet channel, so that the annular air inlet channel is or is not communicated with the lifting pipeline. A groove is formed in the side, in contact with the lifting pipeline, of the sliding stopping plate and is matched with the lifting pipeline for sealing, a ridge arm is arranged at the position, connected to the lifting pipeline, of the upper end of the lifting device, and ventilating pipelines for communicating the annular air inlet channel with the groove formed in the sliding stopping plate are arranged in the ridge arm. The annular channel air inflow type pneumatic lifting device fixes an air inflow position to form central air inflow so as to form a better air-liquid-solid three-phase flow pattern and can also prevent slurry outage and backflow.