the advantage of carbon fiber reinforced polymer (cfrp) is obvious as a common space material for low density, low thermal expansion coefficient and high specific stiffness characteristics, it is the ideal material choice for space optical reflector. mirror structure with honeycomb can achieve high rates of lightweight, as well as high specific stiffness. for f300mm cfrp mirror, accounting of the actual process properties of cfrp, mirror panels laminated based on thermal stability design, honeycomb fabricated using one innovative inlaying-grafting design method. finally, lightweight structure design of the cfrp primary mirror completed, the thermal stability result of the f300mm cfrp mirror achieved is 10nm/degrees c.