The assembled external quick mounting rack system is a new type of support structure suitable for fixing electromechanical equipment and pipelines in metro shield tunnel. It has the advantages of simple process, green environmental protection and no damage to tunnel segments. Based on the engineering example of Fuzhou Metro Line 5, the load-bearing performance of the assembled external quick mounting pylon system is studiedby means of field static test and finite element software simulation. The study shows that: (1) The safety performance of the metro shield tunnel assembled external quick-mounted hanger system can be satisfied by considering the safety factor of 3 times under static load; (2) Local stress concentration occurs at the load action, the intersection of long bolt and groove, and the intersection of groove and lug at the hand hole of concrete pipe slice. The maximum stress point is located at the top of the long bolt, but the maximum stress is less than the allowable stress of the material; (3) When the load acts on the OCS crossbeam, the deformation of long bolt has the greatest influence, but has little influence on the deformation of concrete segment, lug and longitudinal connecting bolt.