Embodiments of this application provide an information transmission method, a terminal, and a network device. The information transmission method in this application may include: determining, by a terminal, a subcarrier spacing corresponding to a synchronization signal, where the subcarrier spacing corresponding to the synchronization signal is a largest subcarrier spacing in a subcarrier spacing set corresponding to a serving cell carrying the synchronization signal; and detecting, by the terminal, the synchronization signal based on the subcarrier spacing corresponding to the synchronization signal. The embodiments of this application can be flexibly applied to different application scenarios.