The invention discloses a scanning method based on a multi-carrier system. In the method, a service base station of a terminal informs a terminal of carrying out carrier scanning by a scanning message, wherein the scanning message comprises at least one of radio-frequency channel information scanned by the terminal and one or a plurality of carriers needing to be scanned by the terminal. The technical scheme of the invention provides a carrier scanning method based on a multi-carrier system, which enables the terminal to finish scanning on a plurality of carriers of a plurality of base stations in the multi-carrier system and provides a reasonable reference value for carrier switching in and among the base stations of the terminal.