To reduce the hazards caused by CO2 leakage during the transmission of supercritical CO2 in a pipeline, it is imperative to investigate methods for leak detection. Supercritical CO2 pipeline transmission is a crucial link in the entire Carbon Capture, Utilization and Storage (CCUS) value chain. Due to the relatively higher Joule-Thomson coefficient of CO2, a significant temperature decrease during leakage can lead to a reduction in pipeline ductility. This, in turn, significantly increases the risk of brittle fracture propagation in pipelines, potentially resulting in pipeline rupture and the dispersion of medium in the pipeline. Through the analysis of CO2 leakage characteristics in supercritical pipelines, this paper proposes methods for both pipeline and station leak detection, selection of relevant instrumentation, positioning of alarm points, and response strategies. The research results can offer reference for the design of leak detection system in the supercritical CO2 transmission pipelines.