With the rapid increase in human population and the excessive utilization of natural resources, humans frequently enhance the production of some services at the expense of others. Therefore, it is important to accurately understand the trade-offs and synergies among ecosystem services and explore land use optimization in order to improve ecosystem services in the Weihe River watershed. In this study, we first simulated and mapped three key ecosystem services at the sub-basin level from 2000 to 2013, including water yield, carbon sequestration, and biological diversity. Then, we quantitatively analyzed the dynamic changes in trade-offs and synergies between ecosystem services by using R language programs and production possibility frontiers (PPF). Finally, the CA-Markov model was used to predict land use change scenarios for 2050. We estimated and optimized the qualities of various ecosystem services in 2050 and the optimal pattern of land use was generated based on the Optimal Pareto Frontier between ecosystem services. The results indicate that:① the water yield increased in the Weihe River watershed from 2000 to 2013. The total quantity of carbon sequestered in the Qinling Mountains and Liupan Mountains was relatively large and the biodiversity quality was relatively high. The Guanzhong Plain region had a large population and urban distribution, the carbon sequestration capacity was poor, and the habitat degradation degree was generally higher. ②There were tradeoffs between water yield and carbon sequestration, as well as water yield and biological diversity. There was synergy between carbon sequestration and biological diversity. ③ The optimal pattern of land use was generated based on the Optimal Pareto Frontier between ecosystem services in 2050. Our research suggested that integrating ecosystem services and trade-off analyses into land system architecture and optimal management is of great value to the sustainable development of the environment and economy.