A micro chain length and temperature (MCLT) wall slip model of polymer was developed on the basis of chain length and temperature. The effectiveness and accuracy of the MCLT slip model were verified through a micro-square-column filling rate experiment for Polypropylene (PP) material and a micro-square-column pressure difference experiment for Polystyrene (PS) material. The difference between the simulated data of the MCLT slip model and the experimental data decreased with decreasing feature size. The accuracy of the MCLT slip model was enhanced by decreasing the feature size. When the feature size was decreased to 200 mu m, the maximum deviation between the simulated filling rate by the MCLT slip model and the experimental result was 8.67%. Moreover, under different shearing rates, the simulated pressure drop by the MCLT slip model was closer to the experimental result than that by the conventional slip model. The micro-scale flow characteristics of the melt were also explored using the MCLT slip model. Melt flow velocity decreased from the center of the micro-channel to the wall, and the wall slip phenomenon was beneficial to the melt flow.