As the country’s demand for clean energy continues to increase

compressed natural gas（CNG） is increasingly used as a clean energy source in various types of vehicles. As a carrier of CNG

steel cylinders are prone to cracks and other defects that seriously affect the safe use of gas cylinders due to their complex use environment. Through abundant inspection practice of compressed natural gas cylinders for automobiles

from the aspects of theoretical analysis and experimental research

the key technical conditions of ultrasonic oblique probe detection are explored to determine the optimal choice. The results show that the combination of small chip probe and chemical paste has the highest detection rate of crack-like defects in automotive CNG cylinders.