The invention relates to a toughening polyethylene-polylactic resin combination which comprises polyethylene, polylactic resin and an impact modifier. The impact modifier comprises a copolymer impact modifier composed of monomers (a), (b) and (c), wherein, the (a) is ethylene and the (b) is a kind or many kinds of alkene with a general formula CH2=CR<1>, wherein, the R<1> is an alkyl which comprises 3 to 9 carbon atoms like propyl, butyl or amyl; the (c) is a type or many types of alkene with a general formula CH2=C(R<2>)CO2R<3>, wherein, R<2> is hydrogen or an alkyl which comprises 1 to 5 carbon atoms like methyl and R<3> is glycidyl. The combination is characterized by favorable impact resistance and tractility, higher rigidity and being environmentally-friendly.