The invention discloses a mesoporous manganese ferrite Fenton-like catalyst and a preparation method and application thereof and belongs to the field of preparation of Fenton-like catalysts. A mesoporous manganese ferrite catalyst is synthesized by using KIT-6 as a hard template agent. A Fenton-like system oxidized wastewater treatment system is formed by prepared mesoporous manganese ferrite and hydrogen peroxide and is used for carrying out efficient removal and mineralization on organic pollutants in wastewater. According to the mesoporous manganese ferrite Fenton-like catalyst and the preparation method and application thereof, the preparation method is simple and efficient, the prepared Fenton-like catalyst has a mesoporous structure and relatively large specific surface area, can be used for providing more adsorption loci and catalysis loci and can be used for efficiently degrading contaminants in a relatively wide pH range (acidic, neutral and even alkaline), and thus, the problems that the traditional Fenton reaction can only occur under acidic conditions and secondary pollution is easily caused due to a large volume of iron mud produced during the reaction are solved; the catalyst can be recycled and is easily separated from an aqueous solution after the catalyst is used so as to recover the catalyst.