Disposable negative pressure excrement liquid drainage device

The utility model provides a disposable negative pressure excrement liquid drainage device. An excrement liquid collecting bag is connected with an input port of a negative pressure ball through a drainage tube; the pasting disc of the collection opening of the excrement collection bag is composed of an adhesive layer and a disc sheet layer which are stacked up and down and bonded into a whole, and the pasting disc integrally comprises a disc body located in the middle and at least four petal-shaped bodies which are evenly distributed along the periphery of the disc body and protrude outwards in the radial direction. A fixed orifice is formed in the center of the disc body through the disc layer, a variable-diameter orifice is formed in the center of the disc body through the adhesive layer, and the aperture of the fixed orifice is larger than that of the variable-diameter orifice; the whole disc body is in a disc shape with the middle protruding upwards relative to the annular periphery, and an arc-shaped tr