Embodiments of the present invention provide a method for determining a measurement gap length and a network device. The method includes the following steps: determining, by a first network device, whether a master eNodeB is synchronous with a secondary eNodeB; and when the master eNodeB is synchronous with the secondary eNodeB, determining, by the first network device, that the measurement gap length is a first length; or when the master eNodeB is not synchronous with the secondary eNodeB, determining, by the first network device, that the measurement gap length is a second length; where the first length is less than the second length.