BST/PLT composite thick films with various content of PbO-B2O3 glass additive from 5mol% to 25mol% were successfully prepared by screen-printing the paste onto alumina substrates. XRD, SEM and impedance meter were used to analyze the phase structures, morphologies and dielectric properties of the thick films. The results showed that the BST phase has no interaction with PbO-B2O3 glass in the composite thick films at 750 oC. Diffusion between PLT phase and PbO-B2O3 glass phase occurs and the c axis of PLT phase in thick films reduces slightly. The high infiltration between the glass phase and particles densify the composite thick films and the uniform microstructure can be obtained in the thick films with PbO-B2O3 glass additive content of 10mol%. Good temperature stability of dielectric properties is achieved with the 25mol% content of PbO-B2O3 glass additive and the variance of the relative dielectric constant in the temperature range between 0oC and 300oC is 15%.