The invention belongs to the field of out-phase fenton catalytic degradation. A preparation method for a manganese-doped magnetic ferrite microsphere with an excellent fenton catalytic performance is characterized by comprising the following steps: 1) by taking NH4HCO3, MnCl2*4H2O, FeCl12*4H2O and ethylene glycol as raw materials and adopting a solvothermal method, synthesizing a ferrimanganic carbonate precursor microsphere; 2) calcining the ferrimanganic carbonate precursor microsphere at high temperature, thereby acquiring the manganese-doped magnetic ferrite microsphere. The invention firstly puts forward taking Fe<2+> as a raw material; the degradation property and the recycling property of the ferrite out-phase fenton catalyst are obviously improved in a doping manner; the acquired manganese-doped ferrite nanometer material has the advantages of strong magnetic response, excellent morphology, excellent fenton catalytic performance and more recycling times; the industrial application prospect is wide.