Optically controlled phased broadband array is a combination of microwave photonics technology and array technology, which not only retains the technical advantages of the array system, but also has the characteristics of large bandwidth, easily forming multiple beams at the same time and anti-electromagnetic interference. Broadband optical beamforming network is the core technology of optically controlled phased broadband array. The basic principles and broadband characteristics of optical beamforming network are introduced. An optical beamforming technology based on optical fiber dispersion is presented. An optical beamforming network experimental system is set up. The experimental system is tested and conclusions are drawn.