In order to implement the rapid repair of damaged largescale composite component using the scanning microwave curing technology, Fe3O4 with good microwave-absorbing performance is chosen as the microwave absorber and the ultrasonic devices are used to disperse Fe3O4 powder in this paper. The effect of Fe3O4 dosage on the curing rate as well as the rate acceleration mechanism is studied. The composite with Fe3O4 epoxy system is prepared for further study and the influence of Fe3O4 on thermal and mechanical properties of glass fiber reinforced composites is studied too. Results show that Fe3O4 can improve the absorbing capacity of the system and thus accelerate the reaction rate. The highest growth rate is achieved with 1% dosage of Fe3O4 and can saved curing time by 24% compared with the pure system. Compared with the pure system without Fe3O4, the glass transition temperature of the counterparts with 1% dosage of Fe3O4 increases by 1.5 ℃, and tensile modulus is improved by 5.8%,whereas the tensile strength is almost the same. Furthermore, the bending strength and the short beam shear strength are improved by 9.0% and 6.5%, respectively.