The invention discloses a method for calculating the power oscillation response of a wide-area AC tie line, and the method comprises the steps: constructing a simplified AC system model; deducing an AC tie line power oscillation response formula under the impact of pulse impact and an AC tie line power oscillation response formula under the impact of step power based on the simplified AC system model; decomposing power fluctuation under a high-voltage DC fault into a plurality of pulse functions and step functions which are superimposed; calculating the AC tie line power oscillation response under each pulse function and the AC tie line power oscillation response und each step function; superimposing all the AC tie line power oscillation responses to form the power oscillation response ofthe wide-area AC tie line under an EHV (extra-high voltage) DC fault. According to the invention, the power oscillation response of the wide-area AC tie line can be obtained accurately through the method, and the method is simple and easy to use. The method is suitable for the research of the power oscillation response of the AC tie line of an AC and DC hybrid power grid currently.