Abstract: CLT/PSA/BOZ composites were prepared by body casting using Si-containg arylacetylene (PSA) and benzoxazine (BOZ) resins as the matrix and Ca_0.7La_0.2TiO₃ (CLT) ceramic as the filler. The results show that the curing shrinkage of the resin is reduced by 57% after the addition of 10% (volume fraction) BOZ. When the packing volume fraction is 50% and the test frequency is 10 GHz, the dielectric constant of the composite material increases to 30.01, the dielectric dissipation factor decreases to 0.0035, the bending strength increases to 63.75 MPa, the thermal conductivity increases to 0.699 0 W/(m·K), and the thermal expansion coefficient decreases to 2.3×10⁻⁵ °C⁻¹. At the same time, the decomposition temperature of 5% mass loss (T_d5) is more than 900 ℃. CLT/PSA/BOZ composites have wide application prospect in high frequency communication, integrated circuit, aerospace and other fields because of their excellent high temperature resistance.