A novel electromagnetic shielding composite was prepared by using metal particle (Cu, Ni, Fe), tetra pak waste, HDPE, and silane coupling agent. Effect of volume fraction of metal particle was studied on mechanical properties, water resistance, and electromagnetic shielding effectiveness. The results indicated that the flexural modulus rises with the increase of volume fraction on the whole; 24 h thickness swelling rate and corresponding water absorption rate both declines with the increase of volume fraction, and the rank of water resistance is Ni/ tetra pak>Fe/ tetra pak>Cu/ tetra pak; volume fraction doesn't improve the SE value significantly, and the rank of SE value is Cu/ tetra pak>Ni/ tetra pak>Fe/ tetra pak.