The invention discloses a manufacturing method and a fixture of an integral bladed-disk wax mold. According to the invention, an integral bladed-disk wax pattern is divided into single blades and a disk shaft. Processes of separated pressing, precise fixture positioning and wax mold welding assembling are adopted. The integral wax pattern is precisely cast. According to the invention, the disk shaft is fixed on an assembling fixture; the blades are sequentially positioned on positioning points on the fixture, and are welded onto the disk shaft. Blade bodies and channel inner walls with high precisions are adopted in the positioning of the blades, such that good consistency is provided for the blades. When the wax pattern is assembled, positioning points are positioned on the blade bodies;blade body positioning points are consistent with processing positioning points, primary standards of cold and hot processing are consistent, such that blade dimensional precision of the whole cast is optimally improved, throat areas between blades are ensured, and flow rate homogeneity is ensured. Positioning parts of the fixture can be adjusted according to measured dimensions of parts, such that the volume of flow rate can be changed according to directional positions of angles of the blades. Therefore, repairing or even rejecting risks caused by unqualified integral mold dimensions are avoided, production period is saved, and production cost is reduced. With the method provided by the invention, hard processes are turned easy, product precision is improved, and production efficiency is improved.