Through the experiment, this paper studied the main influencing factors of swelling capacity of swellable particle. The result shows that for the same kind of particles, the smaller the particle size is, the stronger the water swelling capacity is; for different types of particles, the water swelling rate is quite different. Temperature has little effect on the swelling capacity of swellable particle. With the pH value increasing, the water swelling capacity of swellable particle is enhanced. The influence of salinity on water swelling ability of swellable particle is mainly reflected in the concentration of Ca2+ and Mg2+. The greater the concentration of Ca2+ and Mg2+ is, the weaker the water swelling capacity of the particles is. The polymer concentration has no significant effect on the water swelling capacity of swellable particle, but for the same type of particles, if added polymer, the water swelling rate slows down, and the suspending ability is enhanced. The higher the concentration of the polymer is, the greater the water swelling rate declines, and the stronger the suspending ability is. This result can provide experimental basis for the use of profile control agent by swellable particle for deep profile control.