A lamp rotating structure for a flood lighting vehicle comprises a hydraulic motor, a driving gear, a driven gear and a supporting rod, the hydraulic motor comprises a body and a rotating shaft arranged on the body, the body is used for driving the rotating shaft to rotate, a first through hole is formed in the middle of the driving gear, the rotating shaft penetrates through the first through hole, so that the rotating shaft is sleeved with the driving gear. The driven gear is meshed with the driving gear, a second through hole is formed in the middle of the driven gear, the shape of the axial cross section of the supporting rod is matched with the shape of the second through hole, the supporting rod penetrates through the driven gear, therefore, the supporting rod is sleeved with the driven gear, a light source is arranged at one end of the supporting rod, the driving gear is driven by the rotating shaft of the hydraulic motor to rotate, and the driven gear meshed with the driving gear is driven by the driving gear to rotate, so that the supporting rod is driven to rotate. The lamp rotating structure for the flood lighting vehicle is sensitive in steering and meets the requirement for rapid responses.