A system message transmission method includes: broadcasting a minimum system message, wherein the minimum system information includes first indication information, and the first indication information is configured to indicate a modification period of at least one of second indication information or third indication information. The second indication information is configured to indicate whether target other system information transmitted in an on-demand manner among other system information is in a to-be-transmitted state, and the third indication information is configured to indicate a transmission manner of the target other system information.