The solid equal channel angular extrusion (ECAE) process on polypropylene (PP)/high-density polyethylene (HDPE) blends was carried out. Scanning electron microscopy (SEM) was used to observe the sample structures. Results showed that ECAE process could make PP/HDPE blends to produce orientation structure. Impact performance of ECAE-PP/HDPE samples after ECAE process improved remarkably, especially for ECAE-PP/HDPE (90/10)-O whose impact strength reached 91.91 kJ/m2, 18.1 times higher than that of pure PP and 11.2 times higher than that of PP/HDPE (90/10). The mechanism of enhancing between HDPE and PP was discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39759.