Abstract: Objective: The positioning accuracy during catenary inspection process is the premise to ensure information acquisition validity. To enhance the positioning accuracy of catenary inspection system, an ISP (integrated spatial positioning) method using multiple positioning techniques is proposed. Method: The main positioning technology of catenary inspection system is introduced. The basic structure, system composition, positioning algorithm design process, calibration algorithm design process, and positioning calibration priority determination method for the proposed ISP system of catenary inspection system are introduced. Taking Chongqing Rail Transit Line 4 as an example, tests are carried out for the ISP system. Result & Conclusion: The positioning error of the metro operating vehicle using the MVB (multifunction vehicle bus) signal is approximately 40 m, while that after the vehicle employing RFID (radiofrequency identification) and anchor segment calibration algorithm is around 20 m. The anchor segment calibration algorithm exhibits issues such as misidentification and missed identification, and its stability is inferior to RFID calibration. By utilizing ISP system, the positioning error of the metro operating vehicle is reduced to less than 5 m, demonstrating that the proposed ISP method can effectively improve the train positioning accuracy.