The invention provides a method for detecting the peroxide value of euphausia superba oil. The method comprises the following steps: taking a certain amount of euphausia superba oil m, dissolving the euphausia superba oil in an organic solvent, adding an excessive potassium iodide solution for a reaction, then continuously dropwise adding a sodium hyposulfite solution with the concentration being C to the obtained product and detecting the potential value of the solution till the potential value is stable, during the titration process, discretely recording the titration volume V and the potential value E of the solution, plotting a relation curve of the titration volume V and the potential value E through a second-order derivative method, searching the titration volume Vx of a potential jump point, and calculating the peroxide value of a to-be-detected sample according to the following formula: P'=(Vx-V0)*C/2m, wherein V0 is the titration volume of a potential jump point detected in a blank sample according to the method above. According to the method, problems that the detection accuracy of an iodometric method is low, and many interference factors result from a solvent, the temperature, and a pH value are solved.