The invention relates to a dual mass flywheel assembling process and a dual mass flywheel manufactured through the process. The assembling process comprises ring gear press-in, spindle mounting, lubricating oil injection, secondary mass flywheel assembly assembling, primary side and secondary side butting and welding. A primary mass flywheel of the dual mass flywheel produced through the process does not need to be provided with process holes, and the oil leakage phenomenon is avoided. The dual mass flywheel manufactured through the process comprises a spindle, a primary mass flywheel, a spring positioning plate, a first spring, a second spring, a driving plate, a sealing reed, a cover body and a secondary mass flywheel, wherein the primary mass flywheel, the spring positioning plate, thefirst spring, the second spring, the driving plate, the sealing reed, the cover body and the secondary mass flywheel are coaxially and sequentially arranged on the spindle in a sleeving mode. Rivetingprocess holes are not formed in the primary mass flywheel of the dual mass flywheel, the problem of process hole oil leakage of the primary quality flywheel is completely solved, lubricating oil sealing performance of the finished dual mass flywheel is outstanding, the product service life can be effectively prolonged, and the production cost of enterprises is reduced.