The liquidity, API filtration and sedimentary stability of fibers with different length were tested and analyzed in this paper. The dispersion and dosage of fibers in cement slurry and the compressive strength, flexible strength, tensile strength and the microstructure of cement paste were also discussed. The results showed that the cement slurry with brucite fibers could significantly decrease the liquidity and 45%—50% of API filtration, and barely impacted the sedimentary stability. And the mechanical properties of cement paste were significantly developed for 16.2%, 48.8% and 41.4% by the dosage of 3% fibers for compressive strength, 5% fibers for flexible strength and 8% fibers for tensile strength, after curing in water-bath for 14 days. When using the dispersion means of mechanical shearing and ultrasonic processing, the brucite fibers were uniformly distributed in cement paste as a single filiform fiber that could develop the compactness and confine the micro-fracture of cement paste. The mechanical property gain ratio of cement paste was increased noteworthy by fibers. The tensile compressive strength ratio of 5% fiber reinforced cement improved 27.5%. So the fibers could reduce the brittleness of cement paste as well. However, the brucite fibers with exorbitant dosage would be entanglement and disperse difficultly in cement paste. So the fibers only had filling effect and the strength of cement paste still got a certain amount of increase.