Due to the restriction of aperture effect and the beam deviation, it is the common problem for phased array radar to get wide instantaneous bandwidth under wide scan scope. In this paper, a phased array beam forming system based on the microwave photonic technology was proposed, which can keep high consistency between the beampointing of receiving and transmitting modes and reduce the number of devices. The 16 channels TR community beam scanning system was built and tested. The experimental results show the system can realize beaming scanning under the wide scope of ±30° without beam deviation at Xband, and the beampointing of receiving and transmitting is highly consistent. Combined with the timesharing receiving and transmitting characteristic of the radar system, the scanning and detection capability of the phased array radar system can be effectively improved.