In this work, the axial heat conduction effect on the heat transfer analysis in microchannel flow has been revealed
by the molecule-based temperature sensors technique with different hydraulic diameters. In the results, it can be
found that the axial heat conduction effect enhances the heat flux in the entrance region and increases the
temperature gradient. Moreover, the axial conduction number increases while the hydraulic diameter decreases, and
it shows greater axial conduction effect.