The present invention discloses a stool flush control device, which comprises a main pipe, an independent casing pipe, an indirect connecting pipe, a lock ring and a valve assembly. The main pipe includes flow passage, inclined kerf and screw-thread section. The casing pipe has penetrating hole, a plurality of hollow-out holes, U-shaped tying collar, and two flat kerfs. The lock ring is screw-coupled with the screw-thread section of the main pipe so as to fix in water reservoir tank. The valve assembly connects top flat kerf of the casing pipe. The tying collar ties the manifold. The top of the indirect pipe connects the casing pipe, and the bottom has an inclined opening couplably connecting the inclined kerf of the main pipe. A bolt and a nut are tightened together to press the tying collar so that the valve assembly, the casing pipe, the indirect pipe and the main pipe are closely couple-connected. Thus, the stool flush control device can be easily dismounted and mounted, and fit different sizes of assembly components.