Channel anti-seepage project is one of the important contents for water-saving transformation in irrigation district. In the water-saving transformation to ladder-shaped earth canal of key channel system in original irrigation district, the ladder-shaped section of curved slope foot was selected as section of canal. Because it has a lot of virtues, such as close to optimal hydraulic cross section, fine water condition, hight velocity of flow, ability to convey sand, effectual prevention from seepage, resist of frost-heave performance. Based on this, a system dynamic planning model was built up to carry on vertical-lateral section optimization design to transform irrigation district channel. Comparing and verifying its merits through one instance, the study showed that this design method could reduce the engineering investment in large scale for irrigation district water-saving transformation project.