Abstract: In order to meet the requirement of application and diagnosis of beam for intensive γ-ray radiation field in the calibration laboratory, a radiation field beam simulation model was established and a large area and fast response imaging system was developed, which was composed of high-speed CCD camera and scintillation detector. Through simulation and experiment, the beam parameters were gained under measurement millimeter spatial resolution for the radiation field, including uniformity, divergence angle, the axis of the beam and shutter transit time.