The invention discloses a stratified reservoir thermal density flow tracing method mainly comprising the following steps: drawing landform and grid and inputting information into computer software, selecting a basic equation needed by the flowing incoming flow, and selecting a turbulent model and parameters complying with calculation requirements; setting physical and thermodynamics properties of the incoming flow body according to the real conditions of the incoming flow body; adding a tracking agent in the computer software, and calculating a tracking agent motion convection dispersion equation and parameters thereof; setting the incoming flow tracing agent concentration A; selecting B% of the incoming flow tracking agent concentration as the contour border of the thermal interflow when the calculation is over, thus clearly displaying shape features like the interflow specific thickness and the central line specific position. The advantages are that the novel method can clearly display thermal interflow motion conditions including shape, thickness and central position, thus ensuring calculating accuracy.