A speech recognition method and device are disclosed. The method includes: acquiring a text file specified by a user, and extracting a command word from the text file, to obtain a command word list; comparing the command word list with a command word library, to confirm whether the command word list includes a new command word; if the command word list includes the new command word, generating a corresponding new pronunciation dictionary; merging the new language model into a language model library; and receiving speech, and performing speech recognition on the speech according to an acoustic model, a phonation dictionary, and the language model library. Command words acquired online are closely related to online content; therefore, the number of the command words is limited and far less than the number of frequently used words.