The present disclosure provides a language model training method and apparatus and a device. The method includes: obtaining a universal language model in an offline training mode, and clipping the universal language model to obtain a clipped language model; obtaining a log language model of logs within a preset time period in an online training mode; fusing the clipped language model with the log language model to obtain a first fusion language model used for carrying out first time decoding; and fusing the universal language model with the log language model to obtain a second fusion language model used for carrying out second time decoding. The method is used for solving the problem that a language model obtained offline in the prior art has poor coverage on new corpora, resulting in a reduced language recognition rate.