Abstract: The invention discloses a strontium ferrite-based sacrificial mortar and its preparation method, the strontium ferrite-based sacrificial mortar mainly comprises 720-1000 parts of sulphoaluminate cement, 100-300 parts of strontium ferrite, 600-650 parts of quartz sand, 400-450 parts of water and 0.01-35 parts of superplasticizer. The preparation process is simple, and the strontium ferrite-based sacrificial mortar can be prepared by using a conventional forced single horizontal shaft concrete mixer. The obtained mortar has excellent working performance, compressive strength and corrosion resistance. It can be used in the current third and future fourth generation nuclear power plant core catchers, and has obvious engineering application value.