The invention discloses a three-dimensional weaving method with a cross section being a pipe fitting shaped like the Chinese character 'mu'. The weaving method is characterized in that a fabric structure of the pipe fitting is one layer and more than one layer of two-dimension bidirectional weaving laminated structure or two-dimension three-direction weaving laminated structure. The overall knitting of the fabric structure is conducted by imitating a core model so as to guarantee the size of the inner molded surface of the fabric and prevent yarns from loosening or bending in the fabric. The knitting is divided into an inner pipe part and an outer pipe part, and an inner pipe serves as the reinforcing rib in the pipe fitting cross section. When the three-dimensional weaving method is adopted for preparing pipe fittings with the cross sections shaped like the Chinese character 'mu', mechanization can be achieved in the production process, work efficiency is improved, and quality stability is good; due to the fact that knitting is conducted directly on the core model, fiber in the fabric is tensioned, kinking does not occur, and the utilization rate of fiber strength is high; composite materials for the weaving laminated structure is more resistant to impact and fatigue and good in shear resistance compared with a traditional laminated structure.