3D geological suitability evaluation for urban underground space (UUS) is an important method for the rational development of UUS and reducing the geological risk of development,and it is also a current research hotspot.As an important part of the whole process of 3D geological suitability evaluation,scientific and reasonable establishment of 3D evaluation index system is the premise basis for this. Methods: By combining with the geological problems faced by the development of UUS in Hangzhou,based on the systematic analysis for the characteristics of the impact of each evaluation index on the development and construction of UUS,a 3D evaluation index system with multi-level structure is constructed in three dimension from the 3D structure of the stratum and other aspects.The analytic hierarchy process (AHP) is used to calculate the object weight,consistency test,sort and analysis of the evaluation index.Results:The 3D evaluation index system can be divided into 5 criterion layers and 21 index layers.Compared with the 2D evaluation index system,more evaluation factors can be considered in the evaluation process by integrating 3D geological model and 3D spatial analysis method.The complex 3D geological environment can be better described,which enriches the connotation of 3D evaluation results.Conclusions: The application results of 3D geological evaluation for Qianjiang New Town in Hangzhou based on fuzzy comprehensive evaluation method show that the 3D evaluation index system provides strong guidance for the integration of 3D geological model and 3D spatial analysis method.It also provides strong support for improving the precision and accuracy of UUS geological suitability evaluation in three dimension.