The invention provides an application of a calcium-manganese oxide catalyst in degradation of organic pollutants in wastewater and soil, and relates to the technical field of catalysis and environmental organic pollutant control. The calcium-manganese oxide (Cax(Mn1-aFea)yOz) catalyst is prepared by a sol-gel method and high-temperature calcination, and is used for activating persulfate to generate active substances with strong oxidizing property, such as sulfate free radicals, hydroxyl free radicals, singlet oxygen and the like, so that organic pollutants in water and soil are rapidly oxidized and removed. The catalyst disclosed by the invention is simple to prepare and environment-friendly, the contained elements are Ca and Mn elements which are low in toxicity, cheap and rich in the earth, the metal dissolution rate in the reaction process is low, and the problem of secondary pollution is avoided. In addition, the reaction system formed by the catalyst and persulfate can rapidly degrade phenol, bisphenol A, 2,6-dichlorophenol, parachlorophenol, paracetamol and other refractory organic pollutants, shows good performance in a wide pH range, and has great application potential.