Objective　To investigate the efficacy of treatment of nonunion and delayed union with local injection of nerve growth factor.　Methods　86 patients  with limb fracture nonunion treated in our hospital between January 2014 to January 2016 were in enrolled in this study which was randomized into the control group (43 cases) and observation group (43 cases). Patients in the control group underwent a modular external fixation combined with conventional rehabilitation therapy; patients in the observation group received additional local injection of nerve growth factor treatment. The therapeutic efficiency was compared in the two groups. The maximum diameter of callus within and over 4 weeks, the volume of callus, fracture healing time, quality of life and incidence of adverse reactions were also compared.　Results　Total effective rate was 76.7% and 95.3% in the observation group and the treatment group, respectively, with significant difference detected(χ2 = 8.39, P <0.01); the healing time of tibia, femur, humerus, ulna, clavicle, fibula and radius was significantly shorter in observation group than the control group (P<0.01); no significant difference in the maximum diameter of callus was found between the two groups (P>0.05); 4 weeks after treatment, the maximum diameter of callus in observation group was significantly higher (t=2.576, P<0.01); callus occurrence time, and fracture healing time was significantly earlier in the observation group than in the control group (P<0.01); no significant difference in the incidence of serious adverse events within 8 weeks were found in the two groups of patients (P>0.05).　Conclusion　Clinical efficacy of local injection of nerve growth factor in the treatment of nonunion and delayed union in patients with significant, which can significantly improve the treatment of fractures of efficiency, promoting callus formation and fracture healing, and lowering incidence of adverse reactions in patients, improving treatment safety, making this method worth popularizing in clinic.