The invention relates to general hydraulic engineering, in particular to a silting reduction system for a heavily silt-carrying river reservoir. The IPC numbers are E02B1/00 and E02B9/02. According to the system, a silt-blocking submerged dike is constructed in the reservoir, the reservoir is divided into a clean water reservoir area and a muddy water reservoir area, a silt conveying culvert is utilized for efficiently draining silt-carrying flow in the distance of the upstream of the dike out of the reservoir, the aims of water storage and silt discharging are achieved at the same time, and the rainfall washing distance of the reservoir is enlarged; fine-particle silt turned and overflowed to the area, in front of the dike, of the reservoir through the silt-blocking submerged dike is discharged out of the reservoir through a dike tunnel spillway in a submerged silt pump reservoir desilting mode; according to a wide, shallow and bent silting form occurring on a reservoir area riverway, a reservoir area straight river channel facilitating density flow transport is built in a submerged silt pump dredging mode, and the natural desilting effect of the reservoir is improved. The system is applicable to heavily silt-carrying river reservoir construction and silting waste reservoir reconstructed projects.