The invention provides a method and a device for coverage assessment of a wireless network. The method includes of obtaining test data containing neighborhood signal strength information and corresponding geographic information, collecting the neighborhood signal strength information to corresponding grids according to the geographic information, wherein the grids are obtained by dividing the area to be assessed of the wireless network according to the geographic information; for the grids with the test data, obtaining signal strength of scheduled number of neighborhoods in the grids; obtaining a first propagation model corresponding to the first neighborhood in the scheduled number of the neighborhoods; correcting parameters of the first propagation model according to the signal strength of the first neighborhood in the grids and the distance between each grid and a base station of the first neighborhood to obtain the corrected first propagation model; and calculating the coverage situation of the first neighborhood according to the corrected first propagation model. The method and the device for the coverage assessment of the wireless network can improve accuracy of coverage assessment.