A method for selecting a bearer mode, comprising: receiving (101, 201) indication information of an air interface transmission mode supported by a mobile terminal; sending a session establishment message to a policy and charging rule function entity; receiving an enhanced policy and charging control rule sent by the policy and charging rule function entity; determining (102, 204), according to the indication information and the enhanced policy and charging control rule, an air interface transmission mode allowed to be used by a bearer, wherein the bearer is bound with a service flow of the mobile terminal, and the enhanced policy and charging control rule comprises a type of the service flow of the mobile terminal, and an air interface transmission mode allowed to be used by the service flow of the mobile terminal; and sending (103, 205) a session establishment reply message to a serving gateway to which the mobile terminal belongs, wherein the session establishment reply message comprises the air interface transmission mode allowed to be used by the bearer; wherein before the receiving the enhanced policy and charging control rule sent by the policy and charging rule function entity, the method further comprises: sending a session establishment message to the policy and charging rule function entity, wherein the session establishment message comprises the indication information, so that the policy and charging rule function entity generates, according to the indication information and a policy and charging setting that corresponds to the mobile terminal, the enhanced policy and charging control rule for the service flow of the mobile terminal. receiving (101, 201) indication information of an air interface transmission mode supported by a mobile terminal; sending a session establishment message to a policy and charging rule function entity; receiving an enhanced policy and charging control rule sent by the policy and charging rule function entity; determining (102, 204), according to the indication information and the enhanced policy and charging control rule, an air interface transmission mode allowed to be used by a bearer, wherein the bearer is bound with a service flow of the mobile terminal, and the enhanced policy and charging control rule comprises a type of the service flow of the mobile terminal, and an air interface transmission mode allowed to be used by the service flow of the mobile terminal; and sending (103, 205) a session establishment reply message to a serving gateway to which the mobile terminal belongs, wherein the session establishment reply message comprises the air interface transmission mode allowed to be used by the bearer; wherein before the receiving the enhanced policy and charging control rule sent by the policy and charging rule function entity, the method further comprises: sending a session establishment message to the policy and charging rule function entity, wherein the session establishment message comprises the indication information, so that the policy and charging rule function entity generates, according to the indication information and a policy and charging setting that corresponds to the mobile terminal, the enhanced policy and charging control rule for the service flow of the mobile terminal.