Abstract: The best speed limit value using mathematical modeling and regression analysis method was studied to construct the generalized cost function based on the previous research on the multi-objective optimization road maximum speed limit value model. The Guangzhou Inner Ring Road (IRR) is taken as a research sample. Taking the mortality rate as a constraint condition and combining with the actual road parameters on the curve section and flat straight sections model modification, the best speed limit value of Guangzhou IRR is calculated. The rationality of the optimized speed limit value is proved through applying ArcGIS software platform and the theoretical basis of the optimal speed limit value is proposed.