The large reservoir and its stratified water environment could be simulated in a small laboratory environment. The density currents experiments were carried out under the condition of reservoir temperature stratification. The phenomenon of laminar density currents caused by water temperature stratification under different outlet positions was studied. Besides, exploration has been done about the universal law of the density currents movement and the sediment distribution characteristics in the stratified environment. As it turned out, when the influent sediment concentration was determined and the outlet position was located at the upper, middle and lower levels respectively, the parameters numerical difference was small in terms of the thickness of the density current, the depth of the separation point, the hydraulic jump height and the travel time. When the sediment concentration was determined, the thickness of the laminar density currents was almost constant along the way in the upper outlet position; and the thickness of the same would increase partially due to the sucking effect from clear water in the middle and bottom outlet positions. When the water outlet position was set unchanged, the influent sediment concentration basically did not affect sedimentation ratio. When the sediment concentration was determined, the sedimentation ratio at the upper outlet position was much larger than that at the middle and bottom outlet positions.