DC voltage stability and power coordination control are key factors in ensuring the safe operation of voltage-source-converter-based multi-terminal direct current transmission(VSC-MTDC)systems based on voltage source converters.Although traditional droop control has been widely used in VSC-MTDC systems due to its advanta-ges of communication-free operation and high reliability,its inherent power allocation accuracy is insufficient and the problem of DC voltage offset urgently needs to be solved.This article first studies the influence mechanism of tradi-tional droop control on power allocation characteristics,and constructs an equivalent circuit model of a VSC-MTDC system,focusing on the role of transmission line impedance in power allocation.On this basis,an adaptive droop coef-ficient adjustment strategy based on real-time power margin evaluation is proposed,which dynamically adjusts control parameters to achieve a reasonable allocation of unbalanced power while effectively suppressing DC voltage deviation.The strategy dynamically adjusts the control parameters to reasonably allocate unbalanced power while effectively sup-pressing DC voltage deviations.A five-terminal VSC-MTDC system is constructed on the PSCAD/EMTDC simulation platform for simulation analysis,and the results verify the effectiveness of the proposed control method.