Fabricated building wallboard

The utility model discloses an assembly type building wallboard, relates to the technical field of assembly type buildings, and aims to solve the problems that the assembly type building wallboard is relatively low in mounting and dismounting efficiency and relatively long in required construction period during mounting, and the wallboard is relatively weak in heat preservation property, heat insulation property and sound absorption property in the use process, so that the assembly type building wallboard is relatively poor in heat insulation property and sound absorption property. The composite board comprises a first board body, a second board body and a third board body, and an inner cavity of each of the first board body, the second board body and the third board body comprises a polyester layer, a mineral wool layer and a polyurethane layer. The polyester layer, the mineral wool layer and the polyurethane layer are arranged, the polyester layer has low heat conduction performance and good heat preservati