Tin bath backflow device

A tin bath backflow device comprises a tin bath and a tin pulling pool which are in outflow communication through an outflow port, a slag raking machine is arranged above the tin pulling pool, the tin pulling pool is in backflow communication with the tin bath through an undercurrent channel, and an outlet of the undercurrent channel is formed in the position, away from the wall of the tin bath, of the bottom of the tin bath. Tin ash on a glass plate and the edge of the glass plate floats on tin liquid of the tin bath, the tin pulling pool is communicated with the tail end of the tin bath in an outflow mode through an outflow port, and the tin ash floating on the tin liquid is driven to enter the tin pulling pool from the outflow port in the tail end of the tin bath under the action of a crawler loader through the pulling action of the glass plate; as tin ash floats on tin liquid in the tin pulling pool, the tin ash is cleaned through the tin pulling pool, the clean tin liquid at the lower part of the tin pul