By employing a melt‐sintering method, we prepared a new type of ferrimagnetic glass–ceramic foam (FGCF) using ferrimagnetic glass–ceramic and foaming agent SrCO3. The ferrimagnetic glass–ceramics were fabricated based on pyrite slag by a melt‐quenching method. The effects of foaming agent content, sintering temperature and time on microstructure, magnetic properties, microwave absorption performance, compressive strength, and thermal conductivity of the as‐obtained FGCF were analyzed. This foaming process at 1100°C for 40 min with 3‐wt% SrCO3 provided an FGCF with a bulk density of .693 g/cm3, a porosity of 63.60%, a specific saturation magnetic moment of 5.2 A m2/kg, a compressive strength of 2.61 MPa, a thermal conductivity of .241 W/(m K), and the calculated reflection loss of −12.1 dB for a layer thickness of 9 mm.