After smelting preheated tin ingot which is delivered into melting furnace by delivery roll, the first connector was employed to deliver the liquid tin from the bottom of melting furnace to the holding furnace, where the liquid surface in the melting furnace is 100²00 mm higher than that in holding furnace. Furthermore, the second connector was used to deliver the liquid tin from the bottom of holding furnace to the prilling furnace, where the liquid surface in holding furnace is 30⁵0 mm higher than that in prilling furnace. Through using above measures, the round and sound and pollution-free tin prill with clean surface and uniform distribution can be successfully prepared, which has been applied for electroplating tin steel plate.