A method for predicting the coverage of a 4G LTE (Long-Term Evolution) network based on 3G path measurement data comprises a process for measuring the key coverage indexes of base stations in the existing 3G network and a process for calculating measuring results, wherein the key coverage indexes of each related base station in the existing 3G network are acquired by a test tool, the wireless signal propagation loss of each related base station is calculated, the extra wireless propagation loss, which is caused by frequency variation, of each related base station is measured and calculated according to a freedom space propagation model, the key indexes for evaluating the quality of the 4G LTE network are obtained, a predicting result is obtained, and the predicting result is finally presented by a secondary development tool of a geographic information system. The coverage of the 4G network deployed by the existing 3G network can be predicted, and the deviation degree between the predicting result and a test result after the deployment of an actual test network is within 6dB.