A culvert desilting robot based on high-pressure water driving comprises a machine body, a sliding block, a sliding block driving mechanism, impurity breaking impellers and inner wall cleaning nozzles, wherein the machine body is hollow inside and used for conveying high-pressure water and a cable, the sliding block is arranged on the outer surface of the rear end of the machine body in a sliding and sleeving mode, and multiple driving arms are distributed on the sliding block into an array in an annular mode; multiple driven arm systems are distributed on the machine body into an array in an annular mode, the driven arm systems are correspondingly connected to the driving arms through revolute pairs, and a guiding wheel is arranged on the bottom of each driven arm system; the two sides of the front end of the machine body are each provided with an impurity breaking impeller, and the two impurity breaking impellers rotate in opposite directions; the multiple inner wall cleaning nozzles are distributed at the front end of the machine body into an array in an annular mode, the water inlet ends of the inner wall cleaning nozzles are communicated with the interior of the machine body, and the water outlet ends of the inner wall cleaning nozzles expand outwards obliquely towards the rear end of the machine body. The culvert desilting robot can replace manual work and can be used for cleaning culverts in different sizes, and culvert cleaning efficiency can be improved.