Abstract: To ensure the safe and stable operation of urban gas pipelines, enhance inspection and testing technologies, and promote the development and application of new methods and equipment, the development history of regular pipeline inspections was reviewed. The current status and characteristics of commonly used methods—direct testing, ultrasonic testing, and voltage gradient testing—were summarized. An in-depth analysis was conducted on infrared thermal imaging, high-energy tracer particle testing, Risk-Based Inspection (RBI) technology, and numerical simulation, focusing on their principles, application advantages, and research trends. The applicability and limitations of various testing methods were clarified, and the benefits of emerging technologies in defect identification, risk assessment, and intelligent testing were highlighted. Future directions for the development of inspection equipment were proposed from a technological perspective. Based on a comprehensive analysis of multiple testing technologies, new research ideas are expected to be generated to advance technological innovation and practical applications in this field.