The embodiment of the invention provides a traffic prediction method and device for a mobile communication network, relates to the field of communication, and aims to effectively increase the accuracy of a traffic estimated value. The traffic prediction method comprises the following steps: acquiring a paging amount of a first mobile communication network according to a paging message of the first mobile communication network, and acquiring traffic of the first mobile communication network according to service information of the first mobile communication network; acquiring a linear relationship model between the paging amount and the traffic by a linear regression principle according to the paging amount of the first mobile communication network and the traffic of the first mobile communication network; acquiring a paging amount of a second mobile communication network according to a paging message of the second mobile communication network, wherein the first mobile communication network is different from the second mobile communication network; and estimating an estimated value of the traffic of the second mobile communication network according to the paging amount of the second mobile communication network and the linear relationship model between the paging amount and the traffic. Through adoption of the traffic prediction method and device, the accuracy of the estimated value of the traffic is increased.