The invention discloses magnetic bioactive glass as well as a preparation method and application thereof. The magnetic bioactive glass is obtained by carrying out high-temperature calcination on glass with a core-shell structure, the glass with the core-shell structure is of the core-shell structure which takes ferroferric oxide as a core layer and takes silicon dioxide and calcium oxide as a shell layer to be coated on the core layer, and after high-temperature calcination, the ferroferric oxide is oxidized into magnetic gamma-ferric oxide. The method comprises the steps of adding ferroferric oxide and magnesium oxide into sodium silicate transparent colloid, dropwise adding concentrated sulfuric acid until the pH value is 7-8, reacting at the temperature of 50-70 DEG C, filtering, cleaning, filtering and drying to obtain black solid powder; and adding into a calcium nitrate tetrahydrate saturated solution for heat treatment, and then calcining at high temperature to obtain the magnetic bioactive glass. The method is simple in process, low in cost and relatively low in calcination temperature, the surface of the material has a microporous structure, the specific surface area is larger, mineralization of the material is facilitated, and the biological activity of the material is improved.