The method includes acquiring a target spoken text, where the target spoken text includes a non-spoken morpheme and a spoken morpheme; determining, from a target weighted finite-state transducer (WFST) model database, a target WFST model corresponding to the target spoken text, where output of a state that is corresponding to the spoken morpheme and that is in the target WFST model is empty, and output and input of a state that is corresponding to the non-spoken morpheme and that is in the target WFST model are the same; and determining, according to the target WFST model, a written text corresponding to the target spoken text, where the written text includes the non-spoken morpheme and does not include the spoken morpheme.