The invention discloses a novel rotary spraying stirrer for preventing oil sludge deposition of a crude oil storage tank. The novel rotary spraying stirrer comprises a fixed pedestal, a hydraulic damper outer cylinder, a thrust bearing, a hydraulic damper inner cylinder, a planet gear mechanism, a rotary shell, a top cover and a nozzle; the hydraulic damper outer cylinder and the hydraulic damper inner cylinder jointly form a hydraulic damper; the lower end of the hydraulic damper is connected with the fixed pedestal; an output shaft at the upper end of the hydraulic damper is connected with an output shaft of the planet gear mechanism; the fixed pedestal is connected with the hydraulic damper outer cylinder via a supporting fin. When fluid passes through a rotary spraying stirrer flow channel and is sprayed out of the nozzle, the ejected flow generates a contrary action force on the shell of the rotary spraying stirrer, so that the shell of the rotary spraying stirrer is driven to rotate. The novel rotary spraying stirrer is small in energy loss, stable in speed control, easy to process and produce and low in price, and can be applied to prevention of oil sludge deposition of the crude oil storage tank, occasions of blending and homogenizing crude oil, component oil, lubricating oil and the like in oil product tanks and occasions of cleaning and dredging storage tanks.