Waste plastic film and cement were blended and processed into cylindrical plastic aggregate with screw extruder，and the sand aggregate in cement mortar was replaced with plastic aggregate by equal volume(75%，150%，300%).The effects of plastic aggregate on fluidity，flexural strength，compressive strength，fracture deflection and fracture toughness of cement mortar were investigated.The results show that with the use level of plastic aggregate increasing，the fluidity enhances，the compressive strength and flexural strength of cement mortar reduce.Adding plastic aggregate can increase fracture deflection of cement mortar.Compared with the blank plastic aggregate，the plastic aggregate containing cement can improve the compressive strength and flexural strength of cement mortar.The fracture toughness of cement mortar in which 75% sand is replaced by the plastic aggregate containing 30%(by mass) of cement increases by 571% compared with that of blank cement mortar.