<p>To address the issue of landfill leachate leakage resulting from high-density polyethylene film breakage during operation, a method of utilising eddy current detection to identify leakage locations is proposed. This method can provide data for high-density polyethylene film repair in landfills and reduce the risk of landfill leachate polluting the ecological environment. This research uses the eddy current distribution on a metal surface to design a detection unit with a built-in coil and specimen, explores the response frequency parameters of the sample in the unit, and establishes an array of such units under a high-density polyethylene film. When landfill leachate corrodes a sample, the coil detects corrosion information, which is uploaded to the host for impedance analysis and leakage localisation. First, a two-dimensional positioning model is established to plan the coordinates of the array units. A trilateration method is constructed for inversely positioning the leakage coordinates based on the impedance intensity. A chord intersection algorithm is introduced to optimise the positioning path and eliminate the influence of the multipath effect. A weighted centroid is substituted to calculate the coordinates of the leakage area. Finally, the positioning results are optimised iteratively via particle swarm optimisation, and the leakage area is located precisely via fitness calculations. The experimental results demonstrate that the maximum deviation between the predicted and actual leakage coordinates was 9.4&#xa0;cm, with a minimum of 6.8&#xa0;cm, which meets the specified error requirements. The inversion model is capable of effectively locating leakage position coordinates.</p>