LDPE/ EPDM composites were prepared by mechanical blending method. The effects of two compatibilizers MA/Zn and CPE on the vulcanization properties, mechanical properties, aging resistance and electrical properties of the composites were studied. The results showed that the addition of two kinds of compatibility significantly improved the compatibility of LDPE and EPDM. Compared with CPE, the addition of MA/Zn can improve the properties of the composites better. The mechanical and electrical properties of the composite were improved by the addition of MA/Zn compatibilizer. The volume resistivity of sample L3M2 is the highest at room temperature and 125 ℃, which are 19.8×1013Ω·m and 16.8×1012Ω·m, respectively. Compared with L3, the increase was 26.1% and 25.8%, respectively. The tensile strength is 14.1MPa, which is 90.5% higher than L3.