This paper reviews the research status of existing parallel multi-terminal HVDC line protection, based on the topology of parallel multi-terminal HVDC system with HSS configuration, the line protection configuration scheme is proposed. In order to solve the selectivity problem of parallel multi-terminal HVDC line protection, the reason for the selective blind area of the existing multi-terminal main protection is analyzed in depth. It puts forward a new line protection method, line protection is divided into two segments, through adjusting protection setting value and adding auxiliary strategy, the selectivity problem under normal and faulty COM munication is solved. Finally, RTDS simulation tests prove that the proposed line protection method can effectively distinguish the faults within or outside the area and solve the selectivity problem, when a permanent fault occurs on one line in parallel multi-terminal HVDC system with HSS configuration, all HVDC terminals are not necessary to be stopped, only the fault line needs to be isolated and the remaining lines can continue to run. This proposed line protection method is suitable for parallel multi-terminal HVDC project with HSS.