Abstract: The wave transmission property of the three-dimensional (3D) glass fiber spacer fabric/cyanate ester (CE) composite was investigated by comparison with the 3D spacer fabric/epoxy composite and the honeycomb sandwich composite. The results indicate that the 3D spacer fabric/CE composite shows better wave transmission property than that of both the spacer fabric/epoxy composite and the honeycomb sandwich composite. Moreover, the wave input angle has little influence on the wave transmission property of the 3D spacer fabric/CE composite, and the spacer fabric/CE composite reveals highest wave transmission property with the pile height of 8 mm. When the wave transmits parallel to the warp direction larger transmission property can be observed than that along the weft direction. And the wave transmission property in the range of 8~12 GHz is better than that of 12~18 GHz. Besides, the facesheet reinforcement decreases the wave transmission property due to the wave reflection.