The Fay-Riddell correlation, direct simulation Monte Carlo method, and the Fourier heat transfer expression based on direct simulation Monte Carlo flow field temperature were considered. Cases with different freestream Knudsen numbers (Kn) and Mach numbers (Ma) were studied to provide a new understanding of the classical continuum method to overestimate the stagnation point heat flux in the rarefied region from the microscopic perspective. The related results show that the rarefied effect on the stagnation point heat flux includes three aspects. The temperature jump upon the wall decreases the temperature gradient, reducing the stagnation point heat flux. The translational nonequilibrium was found near the wall, which leads to the failure of the Fourier heat conduction law and overestimates the heat flux. The wall-bound effect makes the Fourier heat conduction law overestimates the heat flux located three times the mean free path away from the wall.