Abstract: A honeycomb sandwich structure embedded with the microstrip antenna of conformal load-bearing antenna structure (CLAS) was designed and fabricated. The mechanical property was analyzed by finite element method (FEM). Compared with the 3-point bending test, the calculated results from FEM are agree well with those from experiments. The influences of honeycomb thickness on the mechanical and electric properties were investigated. The results show that the CLAS with 8~14 mm thick honeycomb has not only have high gain and low return loss, but also have good mechanical properties.