Abstract: The correct method of determining the weight of risk factors is related to the rationality of the risk assessment results of social stability of construction projects. Based on Kendall synergy coefficient, multiple random sampling was used to generate control test samples in the risk questionnaire outcome data corresponding to the selected weighting method. Then the samples are ranked and assigned with points, followed by calculating the average Kendall synergy coefficient and significance testing. The weight determination method corresponds to the one with the highest degree of consistency of the sample data, which is the optimal result of significance testing. The results of example analysis show that Kendall synergy coefficient can realize the quantitative optimization of the weight determination method and ensure the rationality of the weight value calculation results of risk factors.