In SLS sintering forming, laser power and scanning speed are two important process parameters, which directly affect the dimensional accuracy of sintered parts. Using PA2200 powder as the forming material, the influence of laser power and scanning speed on the dimensional accuracy of the sintered part was analyzed. Through theoretical analysis and experimental verification, the best combination of parameters was obtained. The laser power is 40 W and the scan speed is 5000 mm/s. The dimensional accuracy of the sintered parts is obtained by X-direction deviation -0.35 %, Y-direction deviation -0.4 %, and Z-direction deviation -0.25 %.