The invention provides a quantitative evaluation method of a heavy oil steam stimulation water flooded layer. The quantitative evaluation method of the heavy oil steam stimulation water flooded layer comprises the following steps: step 1, determining resistivity of mixed formation water of the heavy soil stimulation water flooded layer according to analysis assay data or logging curve data of the formation water of the water flooded layer; step 2, calculating oil reservoir water saturation Sw according to rock resistivity of a coring well by using an archies formula on the basis of determining the resistivity of the mixed formation water of the heavy oil stimulation water flooded layer; step 3, calculating oil displacement efficiency eta of the water flooded layer according to the calculated oil reservoir water saturation Sw and oil-water relative permeability test data of the coring well; step 4, establishing a heavy oil stimulation water flooding degree judgment standard to realize quantitative judgment and recognition of the water flooding degree of the heavy oil stimulation. The quantitative evaluation method of the heavy oil steam stimulation water flooded layer has better operability, contributes to generalization, and provides a practical and feasible method for fine description of the heavy oil reservoir stimulation water flooded layer.