Abstract: Tunneling Magnetic Resistance (TMR) is an emerging high precision magnetic sensor in recent years. TMR has become a promising magnetic sensor in nondestructive testing field. In this paper, a novel high precision TMR sensors array with wide U-shaped inducer based on ACFM technology is presented for cracks detection. The TMR sensors array and wide U-shaped inducer ACFM system were set up and cracks detection experiments were carried out. The results show that the wide U-shaped inducer induces a broad current field on the surface of specimen. The TMR sensors array and ACFM system can achieve high sensitivity and accurate detection of cracks on specimen. This system can conduct wide area detection and has a high efficiency.