The utility model belongs to the field of building structural members, concrete templates and mould section bars, relates to a prefabricated composite thermal insulation board, a prefabricating mould section bar and also relates to a permanent template taking the prefabricated board as concrete, a splicing assembly comprising the prefabricated board and structural members, wherein one of the structural members has a thermal insulation property and is formed by combining the prefabricated board with concrete, and the other structural member has a thermal insulation property and adds the prefabricated board on the base body of the existing structure. The prefabricated composite thermal insulation board comprises two inorganic non-combustible reinforcing and protective layers (7) and a frame (2) which surrounds a core part (9) made of thermal insulation material and is fastened together with the core part and provided with a mounting groove (13). The core part is arranged between the two reinforcing and protective layers (7). Inorganic non-combustible material is composited at the outer side of the core part of inorganic thermal insulation material to cover the prefabricated board, and therefore, the problem of easily causing fires due to the exposing of combustible materials when the thermal insulation board is placed, transported or installed at a construction site or other places is solved.