Abstract: DC voltage is a crucial indicator for the operation of voltage source converter based multi-terminal high voltage direct current transmission systems, determining the stability of the system and the efficiency of power transmission. To address the issues of poor DC voltage quality and insufficient flexibility in power distribution under complex operating conditions with traditional droop control strategies, an adaptive droop control strategy based on power margin coefficient and voltage deviation factor is proposed. By dynamically adjusting the droop coefficient, it balances the accuracy of voltage regulation and the independence of power distribution, and introduces a damping coefficient to suppress transient oscillations. A four-terminal VSC-MTDC system simulation model is built based on MATLAB to verify that the proposed strategy can more effectively regulate the system voltage under steady-state, power fluctuation, and N-1 fault conditions, improve the voltage quality of the system, and is conducive to enhancing the reliability and stability of the system.