The invention discloses a prefabricated assembled pipe rack. The pipe rack is formed by assembling multiple prefabricated pipe sections, wherein a tenon is arranged at one end of each prefabricated pipe section, and a mortise matched with the corresponding tenon is formed in the other end of each prefabricated pipe section; the tenons and the mortises of the adjacent prefabricated pipe sections are connected in an assembled mode; waterproof sealing gaskets are arranged between the contact surfaces of the tenons and the mortises; flanges are arranged in the circumferential direction of the inner side walls at the two ends of each prefabricated pipe section, and axial drawing holes are preformed in the flanges; the drawing holes of every two adjacent prefabricated pipe sections are formed correspondingly, and every two adjacent prefabricated pipe sections are connected through a connecting piece arranged between the two corresponding drawing holes. The prefabricated assembled pipe rack is simple in structure and convenient to operate, sealing during operation of the pipe rack can be effectively achieved, and the pipe rack is a practical structure for prefabricated pipe rack assembling.