Objective Forearm fractures are more common in upper limb fractures, and the treatment of multisegmental fractures is difficult, with unsatisfactory results of conservative treatment, poor functional recovery, and incisional internal fixation, which is traumatic and prone to delayed healing or even non-healing of the fracture. In our hospital, 11 cases of multisegmental forearm fractures were treated with forearm interlocking intramedullary nailing with satisfactory results. Methods There were 11 cases in this group, aged 19-52 years old, average 36.4 years old; 3 cases of ulnar multisegmental fracture, 2 cases of radial multisegmental fracture, 6 cases of ulnar radial multisegmental fracture; AO typing, 22-C1 type 3 cases, C2 type 2 cases, C3 type 6 columns; 2 of them combined with other injuries. For the radius fracture, a small incision of 2 cm was made at the distal Lister’s node of the radius, a hole was made at the proximal end of the Lister’s node, a suitable intramedullary nail was selected, and the proximal interlocking nail was fixed under the C-arm machine. For ulnar fractures, a 2-cm incision is made at the posterior mid-elbow, a hole is made at the tip of the ulnar hawk, an intramedullary nail is placed, and interlocking nail fixation is performed under c-arm machine fluoroscopy, respectively, and no external fixation is usually required postoperatively. Closed repositioning of the nail was generally used for internal fixation, with limited intraoperative incision and repositioning required in a few cases. The fracture healing time ranged from 8 to 22 weeks, with a mean of 15.8 weeks, and there was no bone nonunion or infection in this group. The fracture healing was delayed in one case, and the fracture healed in 4 weeks after extracorporeal shock wave treatment. Conclusion In this group of cases, all fractures were multisegmental fractures, and most of them were accompanied by soft tissue injuries of different degrees, which were C-type fractures according to AO typing. This will aggravate the soft tissue injury and also destroy the blood supply to the fracture end. The prolonged application of external fixation in plaster will also greatly affect the rotational function of the elbow and forearm. In this group of cases, the ulnar radius was fixed by closed reduction or limited incision forearm interlocking intramedullary nailing, and only and a small number of patients had a certain degree of impact on forearm rotation and extension and flexion function. During surgery, the radial intramedullary nail must be bent preoperatively to form a smooth arc to fit the morphology of the radius. In this group of cases, the fracture is a multi-segment fracture, and the intramedullary nail should complete interlocking fixation of the proximal and distal ends so as to effectively prevent rotation of the fracture end, increase the strength of fixation, and reduce the occurrence of bone discontinuity. The interlocking intramedullary nail fixation method is a good method for treating multisegmental forearm fractures. It has little local injury, firm fixation, and is very beneficial to the functional recovery of the forearm and hand after surgery.