The invention discloses a method for improving thermal processing property of tin bronze. The method comprises the following steps: firstly, weighing raw materials according to mass percentages of chemical elements of tin bronze, melting, and cooling so as to obtain ingots; heating the ingots to 750-800 DEG C, performing extrusion treatment, further cooling to the room temperature, and performing cold-drawing and cutting so as to obtain rods; finally, preheating the rods, and performing stamping treatment, wherein the preheating processing temperature is 750-820 DEG C, and the time is 5-10 minutes. The invention provides the method for improving thermal processing property of tin bronze. According to the method, preheating treatment is performed before stamping treatment, the temperature of preheating treatment and the temperature-keeping time are controlled, a reasonable process route is designed, and the purpose of manufacturing a tin bronze alloy by using a stamping process is achieved; by adopting the method, segregation of a ternary eutectoid structure in the tin bronze alloy can be effectively reduced, alloy crystalline grains can be refined, defects caused in the stamping process can be reduced, and the mechanical property of the stamped tin bronze alloy can be effectively improved.