“The latest technological developments have led to breakthroughs in the field of ultrasonic testing of metal materials. Experts have successfully identified tiny defect echoes in ultrasound detection signals through recursive analysis methods. This method analyzes the ultrasonic backscatter signal through modeling and discovers the influence of defect echo signals on the recursive characteristics of the system. Experimental results have shown that recursive graphs can clearly display the characteristics of defect signals, and specific feature quantities are sensitive to defect signals. This study provides an effective means for ultrasonic testing of metal materials and promotes technological progress in related fields.”