Abstract: The CaCl₂/epoxy resin (E51)/polyamide 6 (PA6) composites with different mass fractions of CaCl₂ were prepared by melting co-extrusion. The crystallization behavior and mechanical properties of CaCl₂/E51/PA6 composites were studied by DSC, rheometer, FTIR and electronic tensile testing machine et al. The confined mechanism was also investigated. The mechanical property results show that with increases of mass fraction of CaCl₂, the tensile strength of CaCl₂/E51/PA6 composites increases firstly and decrease finally. When mass fraction of CaCl₂ is 3%, the tensile strength of composites reaches maximum 82.67 MPa, which is 1.366 times of the tensile strength of pure PA6 (60.5 MPa). The crystallization behavior results show that increase of mass fraction of CaCl₂ decrease the temperature of nucleation, the growth temperature of crystal, the melt temperature and glass transition temperature of CaCl₂/E51 PA6 composites. The density of nucleation and the rate of nucleation also decrease gradually, the crystallization decreases and the degree of crystallinity changes from original 25.22% to 9.90%.