The current research and application status of last line protection in HVDC project are summarized. To overcome its disadvantages in existing engineering application, a modular LLP strategy is proposed. The module is equipped in the controller of each valve group, and it consists of input signals, output signals and corresponding LLP logic. When LLP is activated, if there is no power line connected to the valve group in service through the busbar and moreover certain auxiliary criterion is met, LLP would act and block the corresponding valve group immediately. Theoretical analysis and practical applications prove that the modular LLP can adapt to different kinds of HVDC and AC yard topology. The modular LLP is easier to configure , reuse and test. Without additional investment in hardware, the modular LLP can also achieve good performance in operating speed and reliability, and it will contribute to the safety and stability of the grid.