Abstract: The multi-source adaptive multi source adaptive statcom and line commutation converter (SLCC) significantly reduces the probability of commutation failure. DC transmission systems based on SLCC offer higher transmission efficiency and improved stability, and have now progressed to physical engineering implementation. It is therefore essential to evaluate the reliability of SLCC-based DC transmission systems to provide theoretical support and reference for their safe operation and maintenance. In this study, reliability parameters of components such as the three-phase static reactive power compensation and static var & filter (SVF) are calculated using the frequency and duration method. A reliability evaluation model based on the (goal oriented, GO) method is proposed and integrated with dynamic bayesian network (DBN) to assess the reliability of the SLCC DC transmission system. The time-varying curve of system energy availability is derived, verifying the feasibility and effectiveness of the proposed model and method for reliability evaluation of SLCC DC transmission systems.