The invention relates to a tool pan back-loading type device for changing a tool of a slurry-balanced shield machine under normal pressure, which is applied to the technical field of shield machine engineering machinery. The tool pan back-loading type device for changing the tool of the slurry-balanced shield machine under normal pressure comprises a tool bit, a first seal ring, a tool post, a tool bit fixing sleeve, a tool bit fixing bolt, a tool bar, a cylindrical gate, a grease injection valve, a flushing valve, a third seal ring, a fourth seal ring, a bearing, a large end cover, an oil cylinder and the like; when the tool is in the working state, the tool bit is fixed on the tool bar through the tool bit fixing sleeve and the tool bit fixing bolt; the first seal ring is mounted at thefront end of the tool bar, and the tool bar is matched with the front end of the tool post and is sealed through the first seal ring; the tool bar is fixed on the tool post by the rear end of the tool bar and the tool post through a first fixing screw; the cylindrical gate is fixed on the tool post through the bearing and the large end cover; the grease injection valve and the flushing valve are installed on the tool post; and a serial number is arranged between the cylindrical gate and the tool post. The tool pan back-loading type device for changing the tool of the slurry-balanced shield machine under normal pressure has the advantages of simple structure, reliable working, and capability of conveniently and quickly changing a worn tool under normal pressure (atmospheric pressure) in the shield construction process.