With the rapid development of the China’s economy, energy demand continues to surge. As a major energy consuming nation, China’s development of nuclear energy carries strategic significance for ensuring national energy security. Lead cooled reactor, as one of the reactor types proposed by the GIF, represent a crucial development direction. This work proposed a small modular lead cooled fast reactor called “QJMF-S” focused on safety, miniaturization, modularity and composability. The QJMF-S utilizes natural circulation throughout all operational conditions, significantly enhancing safety, its modular configuration enables the deployment of multiple modules at a single site. It adopts Rankine cycle as the power conversion system, with each module delivering 50MWt thermal power and generating 17.5MWe electrical power. The system can accommodate up to 12 modules simultaneously, with flexible operational configurations to meet diverse user requirements. This paper is structured in two parts: the first section outlined the core and reactor design, thermo-hydraulic design and safety features of the QJMF-S, and the second section demonstrated the deployment scheme of the QJMF-S in special application scenarios by taking the example of industrial steam supply in the heavy oil extraction park. The results show that the advantages of short construction period, low investment cost and flexible power matching brought by the modularized design of the multipurpose lead cooled fast reactor QJMF-S proposed by the CIAE, as well as the multiple passive and inherent safety features, making it suitable for various application scenarios. This work provides certain reference for the design and application of SMRs.