HDPE and UHMWPE were blended in the twin screws extruder with two kinds of screws scheme and the HDPE/UHMWPE films were prepared in the blown film extruder. The mechanical properties, rheological property and crystallization behavior of the blends were discussed. The results showed that UHMWPE could improve the mechanical properties of HDPE film, but made the melt torque of the blends increase. The surface morphology and crystallization behavior of the blends were observed by polarized light microscope. It was found that the dispersion and molten degree of UHMWPE in the blends made by the screws scheme B were improved greatly.