Abstract: ArcGIS software Geodatabase database has become a necessary analysis tool and mapping platform for world famous oil companies, but there are a lot of incomplete information data (or missing data) and exist in the form of null value, which is of great significance to scientific research and production such as statistical analysis and mapping of various oil and gas reserves and to solve the problem of “null value data operation error” in data processing caused by it. On the basis of investigation, analysis and comparison of five common null value processing methods, combined with the practical significance of attributes in GDB relational database and the idea of null value conversion, a four-step process of null value calculation in GDB database in oil and gas field and a new Python programming script oriented to ArcGIS10.0 and above are proposed. Based on the secondary development language of ArcGIS software, experiments on partial data null value operation using VB statements, Shapefile format VB statements, and Python statements are carried out. The experimental results prove the feasibility of Python scripts, and then evaluated and selected a more applicable Python statement null value operation method. Its application to 32 799 oil and gas fields around the world shows that the Python statement null value operation method is feasible, the operation result is correct, and can be applied to data operations with null values in other types, fields and industries, which improves the work efficiency and ensures the correctness and integrity of the analysis data.