The assembly quality and accuracy of main drive of remanufactured TBM is very important to the improvement of the assembly efficiency. Hence, the key technological processes and standards of main drive assembly of remanufactured TBM, as well as the standards and test methods of gear pair meshing quality, are studied and put into practice based on the TBM remanufacturing project of parallel adit of Gaoligongshan Tunnel on DaliRuili Railway. The practice results show that: (1) Before remanufacturing assembly, the remanufacturing quality of assembly parts should be guaranteed first, and then the remanufacturing assembly process and standards should be strictly implemented; the final assembly accuracy should be determined by the gear pair meshing quality detection method, which plays an important role in ensuring the assembly quality and efficiency of the main drive of remanufactured TBM. (2) Considering the detection accuracy, work space, operation convenience and efficiency, the main drive gear pair of TBM remanufactured in the factory adopts "checking method with lead" to measure the tooth side clearance and the "red powder painting method" to measure the contact accuracy. (3) The meshing quality inspection standards for the gear pair of main drive of remanufactured TBM are determined, and the standards include the clearance value of the tooth side of involute spur gear of 1.5 ~ 2 mm (normal direction) and the meshing contact precision is approximately 80% of the tooth width and 70% of the effective tooth surface height. At present, the total driving mileage of the TBM after remanufacturing is 4.4 km, and no abnormal situation occurs in the main drive, which proves the feasibility and reliability of the key assembly processes of the main drive and the meshing quality inspection technology of the gear pair.