The invention relates to an ionic liquid regulation-control bio-enzyme, a method for degrading environmental hormone carbaryl by the same, and a method for determining the degradation rate. The ionic liquid regulation-control bio-enzyme comprises the mixed solution formed by adding chloroperoxidase, quaternary ammonium salt ionic liquids and H2O2 in a phosphate buffer solution with a pH value of 2-5, wherein in the mixed solution, the concentration of chloroperoxidase is 0.005-0.05mu mol.L<-1>, the concentration of ammonium salt ionic liquids is 0.06-0.20mol.L<-1>, and the concentration of H2O2 is 0.05-0.5mmol.L<-1>. According to the ionic liquid regulation-control bio-enzyme, the method for degrading environmental hormone carbaryl by the same, and the method for determining the degradation rate disclosed by the invention, the chloroperoxidase is used as a biocatalyst, the ammonium salt ionic liquids are used as regulation-control factors, the ammonium salt ionic liquids have a cosolvent effect on the chloroperoxidase, and can be used for improving the stability of the chloroperoxidase, increasing the enzyme catalysis speed and increasing the effective utilization rate of the chloroperoxidase; the ionic liquid regulation-control bio-enzyme is capable of effectively improving the solubility of carbaryl and increasing the degradation rate in case of being applied to degradation for carbaryl.