This application relates to the field of wireless communications technologies, and in particular, to a system message transmission apparatus, method, and system, so as to resolve a system message update problem of a terminal device with long discontinuous reception DRX cycle. This application provides a terminal device, including: a receiving module, configured to receive a first system message; and a processing module, configured to: obtain first indication information from the first system message, and update system messages other than the first system message according to the obtained first indication information, where the first system message is periodically sent, and occupies a fixed physical resource location. The first indication information is sent in the first system message instead of a paging message. Because the first system message is periodically sent, and occupies the fixed physical resource location, the terminal device may update the system messages other than the first system message according to the indication information, thereby updating all system messages.