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In this paper, we choose QSn6.5-0.1 tin-bronze alloy that directly manufactured by SLM as material to study the influence of laser power,scan speed and scan space on the relative density of the tin-bronze alloy. An orthogonal process experiment with three factors and four levels on the basis of block forming experiment was designed to study the microstructure and the micro Vickers hardness of the forming parts. The results showed that high relative density of tin-bronze alloy could be got by increasing the laser power and choosing the appropriate scan speed and scan space. And with the optimized process parameters, the relative density of the samples is up to 98.71%. The microstructure is built up of obviously reticular dendrite structure with uniform distribution, mainly containing(α+δ)phase with rich tin and α phase with rich copper. The average micro vickers hardness of the top surface and the side face of the sample are respectively 133.87HV and 130.69HV, which are 45% higher than that of the traditional casting soft state of QSn6.5-0.1 tin-bronze alloy(70HB-90HB). so it had excellent mechanical properties. A three-dimensional wind-round model of tin bronze alloy was manufactured with optimized process parameter. Internal forming quality of wind-round model was researched by computer tomography (MicroCT) technology. And the Vickers hardness of top surface was also tested. The results showed that the internal relative density was high as well as the Vickers hardness of top surface. It is believed that QSn6.5-0.1 bronze alloy parts with fine quality can be manufactured by SLM technology.