Abstract: Conventional mortar can not meet the engineering filling requirements of anti-inclined fractures and defects, and a large number of bubbles will be introduced under the pressure of grouting, and the density of slurry can not be guaranteed. In view of this, a new magnetic epoxy cement (MEC) slurry was developed, which can realize anti-gravity grouting anchoring, guided flow, increase of slurry density and real-time control of slurry viscosity. The SEM,XRD and N₂ adsorption tests were used to analyze the microstructure, hydration products and pore size of MEC slurry under different magnetic fields. The results show that the MEC slurry can be divided into the following two hardening processes: Epoxy curing and cement hydration. The solidified product encapsulate the hydration product and ionize with Ca²⁺ in ettringite (AFt) and Ca(OH)₂ to form a complex to fill the tiny pores in the slurry. When the magnetic field intensity increases from 400 GS to 6000 GS, the pore area and pore number decrease rate reach 77.6% and 76.8% respectively. The test of N₂ adsorption shows that the number of mesopores and macropores and the specific surface area decrease significantly with the addition of magnetic field. The magnetic grout is in line with H₄ hysteresis loop and mainly represents as ink bottle pores. Based on magnetic dipole theory, the force of magnetic particles is simulated numerically. The analysis results show that the pore area can be effectively reduced when the magnetic field intensity is from 2000 GS to 6000 GS.