The invention discloses a method for preparing high-dispersion quasi-spherical M type barium ferrite, relating to a method for preparing the barium ferrite. The method solves the problems in the conventional process for preparing the M type barium ferrite that the shape of a product is difficult to control, the dispersibility of the particles is poor, the particles are easy to sinter and reunite,and the magnetic performance is not ideal. The method comprises the following steps of: 1, preparing a precursor solution; 2, preparing ferrite microspheres; and 3, preparing powder, and calcining the powder at the high temperature to obtain the high-dispersion quasi-spherical M type barium ferrite. The preparation process disclosed by the invention is simple to operate; no template and special preparation process is needed; and the raw materials are safe and easy to obtain, and the cost is low, so that the preparation process is suitable for large scale production. The obtained M type bariumferrite material has good crystallinity, high purity and good dispersibility without obvious sintering phenomenon. The product has a quasi-spherical micro shape, and has excellent magnetic performance.