Abstract: Under the background that pollution charge had been changed to environment tax, to study the optimal design of environment tax rate, this article, from the perspective of organization behavior theory, established an evolutionary game model between local government and pollution emission enterprises on the basis of evolutionary game theory. Then the dynamic adjustment mechanism was put forward on the basis of static environment tax rate and it was proved that the mechanism could effectively control the fluctuation in the evolutionary process. The result shows that dynamic adjustment is necessary;reducing the weight of economic indicators, increasing environment tax rate and reducing the cost of government supervision are effective ways to increase the probability of enterprises'adopting complete pollution control behavior; enterprises with a small production scale and enterprises which were effectively controlling pollution at the initial stage are least likely to control pollution thoroughly in the end. Some suggestions were put forward to solve the problem, such as improving state government's assessment index on local governments, strengthening the cooperation between environmental protection departments and taxation authorities, properly increasing environment tax rate, and strengthening the supervision of emission enterprises with a small pollution scale.