Combined with the previous systematic reviews and the extracted knowledge, the research topics that we find are: Vulnerability Analysis and Risk Assessment, and five corresponding research issues are further explored: Equipment Vulnerability, Regional Vulnerability, Human Vulnerability, Static Risk assessment, Dynamic Risk Assessment. The aim of such categorization is to streamline the investigation of the existing methodologies, instead of emphasizing the boundaries between different research topics, since many research outputs are contributive to more than one area. Section 8: According to the existing research gaps, we believe that future research should focus on the hereunder four aspects: coupling hazard-formative mechanism analysis, modeling the multi-hazard coupling effects with advanced uncertainty analysis approaches, dynamic risk assessment for complex CPI system, and accident prevention from system resilience perspectives.