Abstract: In order to further improve the electrical tree resistance of low density polyethylene (LDPE), montmorillonite (MMT)-SiO₂/LDPE multi-element composite was prepared by melt blending with the organic MMT and surface modified SiO₂ as the inorganic nanofiller. The molecular chain interaction of filler and LDPE matrix was characterized by FTIR. The effects of inorganic fillers on crystallization behavior, crystallization morphology and the electrical tree resistance property of LDPE were investigated. The research results indicate that inorganic fillers are mixed in LDPE in the form of physical entanglement through the long chain of modifier and LDPE matrix. The heterogeneous nucleation of nano-SiO₂ forms small crystal structure which impedes the development of electrical trees, the MMT dispersed in amorphous region has a blocking effect on the development of electrical trees. The combination makes the development path of the electrical trees in the MMT-SiO₂/LDPE multi-element composite more torturous, resulting in the electrical tree resistance of the MMT-SiO₂/LDPE multi-element composite being better than MMT/LDPE and SiO₂/LDPE composites.