The invention discloses a VSC-HVDS flow computational method based on an automatic differentiation (AD) technology, wherein the AD technology is applied to iteration method flow calculation. The VSC-HVDS flow computational method comprises the following steps of: deducing out a steady-state flow model according to the steady-state characteristic of VSC-HVDC; and deducing out a plurality of control modes of VSC-HDVC and a compound mode thereof according to the performance characteristic of the VSC-HVDC; and combining a direct-current network with an alternating-current system based on the steady-state model of the VSC-HVDC to carry out a simultaneous iterative solution. AD is adopted to substitute a traditional hand-coded differential code to calculate a Jacobian matrix, so that the coding efficiency of the code is improved, and the programme development cycle is shortened; finally, the validity of the VSC-HVDS flow computational method is verified by a plurality of example simulations.