In this research, the effects of water-soluble glucoamylase at four concentrations of 2.79, 5.58, 13.95, and 27.9 wt % on CO2 hydrate formation phase equilibrium have been investigated. Traditional isochoric method was employed in 300 mL autoclave to provide these phase equilibrium data. The results are also compared with the hydrate formation in pure water and tetra-n-butyl ammonium bromide (TBAB) solution. The concentration of glucoamylase for CO2 hydrate formation has optimum value. When the concentration of glucoamylase was 5.58 wt %, it has positive effect on lowering CO2 hydrate formation requirements. Compared with TBAB, the promotion effect of glucoamylase is a little bit milder. When the concentrations of glucoamylase were 27.9 and 13.95 wt %, the glucoamylase has inhibiting effect on hydrate formation. Compared with methanol, the inhibiting effect of glucoamylase system is a little bit milder.