A tin leaching process for lead-generation refining alkaline slag is provided. The process includes (1) adding the alkaline slag into a strong-convection reaction kettle containing a solution according to a liquid solid ratio of 3:1, with the temperature inside the kettle being controlled to be 75-85 DEG C during the process of addition, and stirring for another 1.5-2 h after the addition is finished, and (2) discharging the stirred materials, and performing crude separation to separate lead particles and mineral slurry, wherein the lead particles are directly added into an oxygen-rich side-blown furnace and smelted to prepare crude lead, the mineral slurry is pumped into a plate-frame filter press by using a slag slurry pump and subjected to solid liquid separation to obtain an alkaline solution having a high tin content, and a solid isolate comprising about 50% of lead, about 3% of antimony and about 1% of tin, and the solid isolate is used for preparing an auxiliary material of crude lead used for electrolysis. The process is characterized by the temperature and the stirring intensity, wherein the temperature is controlled to allow only the tin in the alkaline slag to enter the solution and allow only a small amount of other elements to enter the solution, the stirring intensity is high so as to prevent materials from being agglomerated and to separate materials attached to the metal lead particles, and the rate of tin entering the solution is higher than 93%.