The bar magnetic particle-ultrasonic phased array automatic flaw detection system is a two-method interconnected device, which can be used independently or in conjunction with other systems. The ultrasonic phased array automatic flaw detection system uses full phased array automatic flaw detection technology to detect flat-bottomed holes, transverse through holes, and related near-surface defects within the bar, meeting the requirements of GB/T4162 for ultrasonic flaw detection processes and acceptance standards for steel bars. The fluorescent magnetic particle flaw detection system uses non-contact composite magnetization technology to detect surface defects in any direction in a single, omnidirectional manner. The system can detect internal and surface defects in bars ranging from 100-500 mm in diameter. It features high precision, high speed, and high efficiency.