The invention provides a tin bath for a float glass forming process. A semicircular or arc-shaped tin bath edge opening is arranged at the tail end of a tin bath outlet; a flow-guiding groove is arranged at the outer side of the edge opening and connected with a bottom recovery box through a flow-guiding pipe; the recovery box is connected with the tin bath through a circulating pump and a liquidsupply pipe; the edge opening is lower than the surface of a tin liquid; the tin liquid flows out along the edge opening and flows into the bottom recovery box through the flow-guiding groove and theflow-guiding pipe; and the tin liquid is then conveyed into a tin bath body located in front of the edge opening from the liquid supply pipe through the circulating pump to form circulation. Accordingto the invention, through the design of the edge opening, the flow-guiding groove and the recovery box, the tin liquid is recovered, and tin is added and placed outside the groove, so invasion of outside air is effectively avoided; and through the structures of the edge opening and a transition roller, the defects of tin staining and tin ash are effectively prevented from generation, and plate breaking is prevented, so the conveying efficiency of the transition roller is improved, and the surface quality of a glass plate is guaranteed.