By constructing the evaluation index system of water resources and social economy, the synergy degree of water resources and social economy system in the Yellow River Basin is calculated, and the influence factors are analyzed by using the fixed effect model. The results showed that both the water resources and socio-economic development index showed a significant upward trend, and the socio-economic growth rate was higher than the water resources development rate. The whole Yellow River basin is in a slightly coordinated state, and the development of water resources lags behind the development of social economy. The synergy degree of Shandong, Henan, Sichuan and Shaanxi is ideal, while the synergy degree of Inner Mongolia, Gansu, Qinghai, Ningxia and Shanxi is low. The number of students in colleges and universities per one hundred thousand people, the amount of surface water resources, the utilization rate of water resources, the daily treatment capacity of urban sewage and the transaction amount of technology market have a positive impact on the collaborative development, while the urbanization rate has no significant impact on the collaborative development.