As the primary means of refined products transportation, multi-product pipeline plays a vital role in connecting refineries to local markets. Once disruptions occur, it will cause security issue on oil supply to downstream markets, even on the economy and stability of society. Based on the conventional reliability theory and detailed scheduling method of multi-product pipeline considering hydraulic constraints, this paper firstly proposes a multi-module systemic approach for the supply reliability analysis of multi-product pipeline under pump units failure conditions. Pump units are important corollary equipment in multi-product pipeline and their failure would affect the pipeline normal operation and downstream oil supply greatly. The approach includes three modules, namely, pump units analysis module, pipeline system analysis module and reliability evaluation module. In the pump units analysis module, Failure Mode and Effects Analysis (FMEA) method is adopted to analyse the correlations between pump units failure modes and causes. The Monte Carlo simulation method is employed to generate different failure scenarios based on the estimated failure rate of pump units. In the pipeline system analysis module, the detailed scheduling method of multi-product pipeline is adopted to calculate the maximum supply capacity for all delivery stations under a specific scenario. Due to the difficulty in solving detailed scheduling problem considering hydraulic constraints directly, two mixed integer linear programming (MILP) models are established. In the reliability evaluation module, the indexes of shortage, probability and adequacy are calculated to analyse the supply reliability quantitatively from global perspective and individual perspective. Finally, the proposed approach is applied to a real-world multi-product pipeline in Zhejiang, China. It is proved that this approach could provide significant guidelines for the supply reliability analysis of multi-product pipeline.