Just go to the marriage registration office of the Civil Affairs Bureau to reissue the marriage certificate! There may be some small procedures on your way to reissue the certificate: for example, ask you (your lover) to issue the certificate of your work unit, or if you don't have a unit, ask your residence, that is, the neighborhood Committee to issue the certificate; Personally, I think you'd better go to the Civil Affairs Bureau to inquire about the relevant issues and procedures you need to reissue your documents, as well as some information and how long it will take to reissue your documents. (If it takes too long to get the certificate or reissue the certificate), you can bring all relevant information and explain your situation, and see if you can ask the leader (person in charge) of the Marriage Registration Office of the Civil Affairs Bureau to help you open a certificate of marital status first. Good luck!