With the advent of the 5G era, the widespread use of various electronic devices has led to serious electromagnetic pollution problems. It is urgent to develop high-performance electromagnetic wave absorption materials to solve the above problems. In our work, nickel zinc ferrite (Ni
0.6Zn
0.4Fe
2O
4) nanoparticles were grown on reduced graphene oxide (rGO) sheets by a simple in situ growth method, and a series of Ni
0.6Zn
0.4Fe
2O
4/rGO (NZFO/rGO) absorbers were prepared by adjusting the dosage of rGO. The minimum reflection loss (RL) of NZFO/rGO-1:0.5 at 11.24 GHz is −60.72 dB with the matching thickness of 2.98 mm. In addition, when 5 wt% NZFO/rGO-1:0.5 composites were used to prepare the modified epoxy resin coating, the minimum RL value of the cement-based materials coated the coating is −42.2 dB, which is 90.95% lower than the minimum RL value of pure epoxy resin specimen; When the dosage is 3 wt%, the effective absorption bandwidth (EAB) value is 8.88 GHz, and the absorption bandwidth can reach 13.2 GHz when the RL value is less than −5 dB.