Based on the investigation and discussion of the lighting system in the smart city of Tianjin, this paper analyses the existing problems of the road lighting system and summarizes the solutions. Relying on DIALUX software to build the urban road model foundation space to simulate the urban lighting system. Analysis the data, using the DIALUX Lighting computing Wizard to find out the best application strategies for each kind of the light source. Establish the contrast light source, and combine with the new light source parameters, find out the best application strategies for the LED light source. Based on the best application strategies, analysis and simulate the data, at last calculate the relevant benefits, including the economic benefits, the energy benefits and the environmental benefits.