The present invention provides a method and device for data shunting and relates to the technical field of communications. The present invention solves the problem that the requirements for the Service Quality can not be satisfied, because the shunted data can't be transmitted in the shunting network based on appointed Service Quality; and the reliability of data transmission and the system resource utilization are decreased. The method concretely comprises the following steps: the first network device of the first network determines the second Quality of Service parameter of the second network according to the first Quality of Service parameter of data to be transmitted in the first network; the first network device transmits some or all of data to be transmitted to the second network device of the second network according to the second Quality of Service parameter. The method can be applied to data shunting.