Abstract: Design of the micro-irrigation system under different terrain conditions is a subject widely concerned. A computer simulation program was developed for simulating the micro-irrigation pipe network system under different terrain conditions. Applying the generation method of curve face and measured data, physiognomy maps were achieved. The layout of pipelines was designed and the height levels of pipelines in different positions were computed. Calculation of parameters of pipe network system and hydraulic balance was accomplished automatically. In order to validate the reliability, an orchard drip irrigation system on flat plot was simulated. Results were consistent with designs. As the pipelines layout along the relief of complicate plot for example, the hydraulic analysis results showed that the needed head pressure of system and the pressure regulation range at all nodes were larger than that in flat plot.