Based on the selective laser sintering (SLS) technique, the influences of the process parameters including scanning speed, laser power, layer thickness, scanning spacing, and preheating temperature on the strength and dimensional precision of SLS prototype parts are analyzed under different process parameter combinations. The study results show that, all the sintering process parameters can affect the sintering strength and dimensional precision of prototype parts, and there exist interactions between various factors. When the laser power is 40 W, the scanning speed is 2500 mm·s-1, the scanning spacing is 0.15 mm, the layer thickness is 0.20 mm, and the preheating temperature is 60 ℃, the optimal sintering strength and dimensional precision can be obtained. Based on these results, by combining the traditional sand casting method, a new advanced-construction-machinery hydraulic valve is rapidly casted, which verifies the feasibility of rapid casting process of hydraulic components based on the SLS process.