Chlorobenzene is a synthetic organic compound. It is widely used in the industrial and agricultural productions. It is difficult to be degraded by indigenous microorganisms in the groundwater environment. Immobilization microbial technology is widely used in the water treatment in recent years. Microorganism is immobilized in polymeric gel. It forms an isolated environment for the microorganism. The activity of microorganism and the efficiency of pollutants degradation are improved. The effect of bioaugmentation is enhanced. By using static factors-choosing experiment and dynamic simulation experiment, it is confirmed that PVA-SA composite gel fixed microbial degrade chlorobenzene-contaminated groundwater is more effective than free microorganisms and indigenous microorganisms do. And it is concluded that the bigger ratio of the aquifer medium size to gel size, the more conducive to PVA-SA composite gel migration in groundwater is. It is also concluded that the smaller the gel size is, the higher chlorobenzene degradation efficiency is. For the best degradation effect, PVA-SA composite gel immobilized conditions are PVA concentration of 80g/L, CaCl₂ concentration of 10g/L, the ratio of embedding medium to the broth volume is 30:1, and SA mass fraction is 1.0%.