The Water-Energy-Carbon Emissions (WEC) nexus has been drawing increasing attention. However, very few studies, to date, were conducted to comprehensively review the assessment approaches, challenges and trends of future works for regional and sectoral CWC nexus. This paper aims to analyse and review the WEC nexus assessment methods, challenges of WEC network management and ways to go in the future. Eight different kinds of WEC nexus assessment methods are introduced, as well as their advantages and drawback. Five future work directions of WEC nexus assessment are proposed. This study provides a better understanding of the WEC nexus and more approaches to assess the WEC nexus.