Abstract: Along with the rapid development of aviation and aerospace manufacturing technology,the application of sophisticated components is more and more widely.In the immersion ultrasonic C-scan testing of complex or large thickness,the multi-zone focus for different thickness of the testing area with the corresponding parameters is often applied.The developed four-channel immersion ultrasonic C-scan testing software CScanPro can achieve the multi-zone focus detection of four-channel simultaneous imaging scan,and improve the detection efficiency.This software is practical,stable and user-friendly.CScanPro can also be applied to non-focused four-channel ultrasonic C-scan inspection,it is installed and used in three ultrasonic C-scan testing systems,and the test results are accurate to meet the test requirements.