With the increasing shortage of power transmission corridors, hybrid high voltage direct current transmission (HVDC) system with multiple terminals is expected to be the mainstream trend of HVDC systems. Reliability evaluation of the HVDC systems has become an important link in power system planning, design, and operation. In this paper, the typical connection structure and operation mode of the hybrid HVDC system with multiple sending terminals is analyzed. The corresponding reliability evaluation method under subsystem division is proposed. Based on the reliability block diagram and state enumeration method, the capacity and probability of the transmission system under each fault state are analyzed, and then the forced energy unavailability (EU) index is used to quantify the reliability of the hybrid HVDC system with multiple sending terminals. The applications of the model are illustrated with numerical examples, and the influence of the reliability of the key equipment is analyzed.