The K2O(n-x)B2O3-xSiO2/Al2O3 low temperature Co fired Ceramic dielectric materials was prepared by adding Al2O3 to K2O(n-x)B2O3-xSiO2,which was made of 1 500 ℃ high temperature melting method. The influence on material structure and performance with the change of proportion of SiO2/B2O3 and addition of glass were studied systematically. The results showed that the crystallization of SiO2 was restrained in the class Y, the dielectric constant and dielectric loss of composite material decreased to a certain degree, and the bend strength of the composite material also decreased with the increase of the B2O3.