1. A text conversion method, comprising: acquiring a target spoken text, wherein the target spoken text comprises a non-spoken morpheme and a spoken morpheme, and characteristics of the spoken morpheme comprise an inserted morpheme, a repeated morpheme, and an amending morpheme; determining, from a target weighted finite-state transducer (WFST) model database, a target WFST model corresponding to the target spoken text, wherein 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, wherein the written text comprises the non-spoken morpheme and does not comprise the spoken morpheme.