Experimental study on the preparation of magnesium oxysulfate cement-based composites using waste locust powders to replace non-renewable magnesium oxide

•Waste locust residue with dosage of 0 %∼25 % was added into MOSC by mechanical mixing to prepare new composites.•The slurry fluidity, flexural and compressive strength, displacement before fracture, water resistance and microstructure were studied.•The optimum replacement level of 20% to replace MgO resulted in high utilization of locust wastes, reduction of raw materials, and good mechanical properties.