The invention discloses a method for determining the wireless network of a multiaerial system, belonging to the wireless technology field. The method comprises the following steps: determining broadcast wave beam shaping figures which correspond to all cell antennae according to the attribute of the range of all cells needing to be covered in a wireless network; determining broadcast wave beam weight values of all the cell antennae according to the determined broadcast wave beam shaping figures of all the cell antennae; replacing the original broadcast wave beam weight values of all the cell antennae by the determined broadcast wave beam weight values of all the cell antennae; and determining the coverage area of the wireless network according to the replaced broadcast wave beam weight values of all the cell antennae. The invention also discloses a device for determining the wireless network of the multiaerial system. Through the method and the device for determining the wireless network of the multiaerial system, the inclination angle, the direction angle, the hanging height, and the like of the antennae do not need to be adjusted manually, and corresponding accurate broadcast wave beam shaping figures can be obtained, thereby an immediately constructed network can be more accurately simulated, and the advantages of the multiaerial system can be fully exerted.