The disclosure discloses a method and an apparatus for transforming a working mode in a Cognitive Radio (CR) system, which are used for solving the technical problem that a subsystem maliciously occupies the spectrum resources which are temporarily unused by other system in a system adopting a CR technology. In the disclosure, a network side measures the demand degree of each cell on borrowed spectrum and sets a conditions of enabling and disabling the CR working mode to determine whether to perform working mode transformation on the cell and specify a network allocation method for a mobile terminal in a corresponding working mode, so as to coordinate the allocation of the spectrum resources, and avoid the abuse of the borrowed spectrum resources; the CR working mode of the cell with low demand degree is disabled by the network side; the borrowed spectrum resources of the cell are released; and therefore, more borrowed spectrum resources are available to the other cells having a higher demand degree on the borrowed spectrum, and the overall performance of the system is improved.