Abstract: Using mixed programming of VC++ and Matlab, this paper developed a simulation system of ultrasonic phased array imaging, and achieved a easy ultrasonic phased array simulation environment to operate. Simulation system composed of three modules, the probe module sets the probe parameters and can be used to analyze its sound pressure and directivity; Defect module simulates defects and chooses defects imaging method; The imaging module, which is based on the probe module and defect module, completes ultrasonic waves transmitted by the probe, controls the beam deflection focusing, and then performs series of processing of the echo signals received by the probe, including envelope extraction, logarithmic compression, DSC transform and so on, and finally shows the image graphically.