A decision support system for field water management based on crop growth model (DSSFWM) was developed. The structure and function of DSSFWM, principles and methods of management objective determination and water management decision-making were introduced in details. The case study of irrigation management during the winter wheat growing season at Zhengzhou eco-site in 1991,1992 was conducted to analysis the optimum irrigation scheduling. The results showed that water-saving, high yield and high efficiency could achieved with three times irrigation at tillering stage before winter, green-turning stage and jointing stage. DSSFWM can enhance the judgment of users for field water management and help improve the efficiency of decision-making.