Non-isothermal crystallization behavior of copper/poly(ethylene oxide)/low density polyethylene (Cu/PEO/LDPE) composite was investigated by using differential scanning calorimetry, and the feasibility of various models for determination the non-isothermal crystallization kinetics and activation energy of its LDPE matrix were evaluated in this work. The results show that the crystallization of its LDPE matrix was retarded by the addition of PEO with a higher molecular weight and accelerated by cooling with a larger cooling rate. The results also show that the crystallization kinetics of the LDPE matrix was not affected by the PEO molecular weights, but the crystallization activation energy of the LDPE matrix was affected and increases with the increase of PEO molecular weight. Additionally, Avrami-Ozawa equation is desirable to determinate the non-isothermal crystallization kinetics of their LDPE matrix, and isoconversional method modified by Vyazovkin is more suitable to calculate the non-isothermal crystallization activation energy of their LDPE matrix.