Based on orthogonal tests, the optimization method of binder jetting forming Ti6Al4V alloy process was investigated, and the powder gradient optimization strategy was proposed, revealing the control mechanism of fine powder introduction on the pore structure and forming performance of the samples. The influence of printing process parameters on the forming properties of green part is investigated by orthogonal test, and the correlation relationship between the properties of green part is constructed based on the normalization analysis method to obtain the optimal process parameters, and the particle size distribution is further regulated by the strategy of coarse and fine powder gradient to investigate the influence of fine powder content on the properties of green part and sintered parts. The results show that the layer thickness has the most significant effect on the properties, followed by the inkjet density, and the rotational speed has a higher effect on the properties of the green part than the horizontal speed. The optimum process parameters were 100 μm layer thickness, 85% inkjet density, 100 mm/s horizontal speed and 2.0 r/s rotational speed. When the mass fraction of fine powder is 10%, the green part performance was optimal, with a relative density of 52.22% and a compressive strength of 3.27 MPa. When the mass fraction of fine powder is 20%, the sintered parts achieve the optimal mechanical properties, with a compressive strength of 642.94 MPa and a Vickers hardness of 420.68HV. When the mass fraction of fine powder is increased to 30%, the relative density of the sintered body reaches 93.11%. This provides a reference for the optimization of binder jetting forming process parameters and the regulation of sample properties of Ti6Al4V alloy.