The invention relates to a developing and governing method for a sandy wide channel canal/shoal/pool. A narrow river channel is formed by two main dikes (new flood dikes) which are constructed between the prior flood dikes at two sides of a sandy channel segment along the riverway trend, and large dams are constructed at the upstream and the downstream. A water supply and sand diversion canal is constructed at the inside or outside of at least one of the main dikes in the narrow river channel. A conveyance and navigation canal is constructed outside one or two sides of the narrow river channel. The conveyance and navigation canal is adjacent to the water supply and sand diversion canal or the conveyance and navigation canal, or the conveyance and navigation canal is a split type. The bottomland and the pool surrounded by the diking are changed from the shoal area between the main dike or canal dike and the prior flood dikes. The bottomland can be a permanent site for living, production, construction and development. The long-term reserved pool is capable of storing water resource and supplying water in non-flood season, storing floodwater and replenishing dryness in flood season, and detaining and storing the flood. The developing and governing method for the sandy wide channel canal/shoal/pool effectively prevents from flood, treats and uses slit, ensures the security in flood prevention, and supplies enough rinsing water source; the water service cost is low, and the method is capable of developing and utilizing the resources such as hydraulic power, shipping, and tourism, etc. in the channel segment, and the method has a positive meaning in improving environment.