Abstract: To address issues with mechanical cleaning of bottom sediments in a crude oil storage tank at a crude oil station in Xinjiang—such as seasonality and limited precision in cleaning and agitation—laboratory tests were conducted to optimize the process conditions for mechanical cleaning using thin oil of the same type. The tests provide a basis for establishing precise process parameters for the cleaning operation. Results indicate that the oil sludge is a non-Newtonian, pseudoplastic fluid. When the oil sludge is cleaned with thin oil of the same type, the oil sludge/thin oil solid-to-liquid ratio is the key factor in reducing sludge viscosity. Optimal cleaning conditions include: a sludge-to-thin oil volume ratio ranging from 2:1 to 1:1.1, a cleaning temperature of 25 ℃~35 ℃, and a cleaning time of 30~60 minutes. Under these conditions, the apparent viscosity of the sludge can be reduced to as low as 39.86 mPa·s, facilitating easy removal from the tank.