The invention discloses a self-elevating conveying and distributing system and a construction method of a cast roller compacted concrete dam. The system comprises a dam outside feed device, a dam inside and outside transition belt, a dam inside conveying belt, a traveling unloader and a conveying belt jacking device, wherein the dam outside feed device is connected to the dam inside and outside transition belt, the dam inside and outside transition belt is connected to the dam inside conveying belt, and the conveying belt jacking device is used for supporting the dam inside conveying belt. Theconstruction method includes the steps: 1 mixing roller compacted concrete materials; 2 conveying the roller compacted concrete materials; 3 spreading the roller compacted concrete materials; 4 compacting the roller compacted concrete materials; 5 detecting compactness; 6 performing layer-by-layer construction until dam body construction is finished. According to the self-elevating conveying anddistributing system and the construction method of the cast roller compacted concrete dam, the dam outside feed device, the dam inside and outside transition belt and the dam inside conveying belt arecooperatively used for conveying roller compacted concrete, the transfer link of the roller compacted concrete in the conveying process is decreased, and the casting quality of the concrete can be effectively ensured.