The invention relates to the field of door and window manufacturing, in particular to a multifunctional casement window composed of transverse frames and vertical frames. The transverse frames are set as the upper frame, the middle frame and the lower frame according to different positions, and the vertical frames are set as the left vertical frame, the middle vertical frame and the right vertical frame, wherein the left vertical frame is composed of an upper left vertical frame and a lower left vertical frame, and the right vertical frame is composed of an upper right vertical frame and a lower right vertical frame. An upper window body part of the casement window is composed of the upper frame, the middle frame, the upper left vertical frame and the upper right vertical frame, and glass is arranged in the middle of the upper window body part. A main window body part of the casement window is composed of the middle frame, the lower frame, the lower left vertical frame and the lower right vertical frame. Two window sashes with the same structure are connected on the edges of the main window body part through hinges. A plurality of heat insulation strips are connected between corner braces, so that the heat insulation effect is achieved; and meanwhile, the window sash glass made of double-layer glass has the better heat insulation effect and also plays a positive role in the overall effect of house decorating.