To optimize the comprehensive properties of Ni-Si precipitation strengthened phosphor bronze, the impact of the Ni/Si mass ratio and heat treatment process on a Cu-8Sn-0.1P-1Ni-xSi alloy was explored. High resolution field emission scanning electron microscopy and transmission electron microscopy were used for microstructural characterization. The results indicate that the properties are influenced by the Ni/Si mass ratio, attributed to the formation of various second phases. Simultaneously, by influencing the diffusion rate, the microstructures and properties are influenced by the solid solution treatment. The strength is enhanced by precipitated nanoscale particles during the aging process by influencing the motion of dislocations. Ultimately, excellent comprehensive properties, including ultimate tensile strength, yield strength, and elongation of 866 MPa, 772 MPa, and 8.7%, respectively, are obtained in the Cu-8Sn-0.1P-1Ni-0.227Si alloy.