The invention discloses a method for determining direct-current interference of a buried metal pipeline with a damaged protective layer. The method comprises the following steps: determining a virtualboundary according to obtained characteristic parameters of a grounding electrode and the buried metal pipeline to be analyzed, and determining a nonlinear boundary; determining potential distribution of the virtual boundary and simplified current distribution of the nonlinear boundary; calculating potential distribution of a soil side on the nonlinear boundary in a soil area; determining a simplified polarization potential on the nonlinear boundary; determining potential distribution of a metal side on the nonlinear boundary according to the simplified polarization potential and the potential distribution of the soil side; calculating process current distribution on the nonlinear boundary in a metal area; and determining a target polarization potential on the nonlinear boundary when a difference value between the process current distribution and the simplified current distribution is not greater than a preset convergence threshold value. The method for determining the direct-currentinterference of the buried metal pipeline is high in precision and high in efficiency.