Composite insulation board

The utility model discloses a composite insulation board which comprises a housing, a carbon crystal electric heating plate is installed in the housing, the housing is formed by butt joint of two cover plates which are connected through a connecting structure, and a reflecting layer, an insulation layer and a decoration layer are sequentially arranged on each cover plate from inside to outside. The reflecting layer is a reflecting film or a metal film arranged between the carbon crystal electric heating plate and the inner wall of the cover plate, the heat preservation layer is a heat preservation material layer which is integrally and fixedly connected into an end face plate of the cover plate and surrounds one side of the carbon crystal electric heating plate, and the decoration layer is a decoration face plate wrapping the cover plate. By means of the wrapping type structure of the housing and the arrangement of the reflecting layer and the heat preservation layer, heat loss can be effectively reduced, and