In this work, an experiment was carried out to investigate the preparation condition of anosotropic Fe-deficient M-type Ca-Sr system ferrite with optimum magnetic and physical properties using the raw material Fe2O3 from steel industrial iron oxide waste. The compositions of the calcined ferrites were chosen according to the stoichiometry Ca1 − x−yLaxSryFe10.9CozO19, where x was varied between 0.05 and 0.85, y between 0 and 0.18, and z = 0. The effect of CaO, SiO2 and Co3O4 inter-additives on the Ca-Sr system ferrite was also discussed in order to obtain low-temperature sintered magnets. The optimum condition of making magnets and some properties of a typical specimen are as follows. The preparation condition: condition: composition Ca0.37La0.45Sr0.18Fe10.9Co0O19, calcination condition 1240 °C × 1hr in atmosphere, low-temperature sintering condition 1210 °C × 1hr in atmosphere, inter-additives Co3O4 = 1.85 wt%, CaCO3 = 1.7 wt%, SiO2 = 0.6 wt%, CaO/SiO2 = 1.59. The magnetic properties of Br=5425 Gauss, bHc=4320 Oe, iHc=4602 Oe and (BH)max=5.26 MGOe were obtained for Ca-Sr system hard magnets with relatively low cobalt content. The unremarkable steel industrial iron oxide waste is recycled produce high-end permanent magnets under output power < 1 kW, which will eventually be used in high-efficiency motors. This is a specific manifestation of "garbage turning into gold" and is one of the best models of circular economy.