The invention relates to a structural internal part used in the gas-liquid mass transfer processes such as rectification and absorption, especially relates to a plate-type tower fixed valve element capable of effectively raising the surface area of gas-liquid two-phase contact. The fixed valve is produced through one time punching by a tray plate, and comprises a valve cover and four support feet which are evenly distributed at a 90 DEG circumferential direction, the shape of the valve cover and a valve aperture of the tray plate are in a cross shape formed by two orthogonal rectangles, semi-circular arc tooth edges are punched by each edge of the valve cover and the support feet, a tongue shape guiding aperture is provided at the upper part of the valve cover simultaneously. By using the above the structure, larger wetting circumference of the fixed valve and larger gas phase channel outlet can be ensured under the same open area of the tray plate, the surface area of gas-liquid two-phase contact can be effectively increased, and the mass transfer can be reinforced. In addition, the unique cross orthogonal structure is capable of improving the liquid phase flow of a plate-type tower arc zone by changing an included angle of a normal plane of two support feet relative to the fixed valve and liquid flow direction.