This paper calculated the effect of environmental taxes levied on small and micro businesses using data from 37small and micro industrial enterprises in Hunan province. Taking COD as an example, a thorough comparison of pollution emissions and the economic benefits of the small and micro businesses, and find total samples' pre-tax profits accounted for 1.09% and the emissions rate is 32.65%, indicating that the small and micro businesses is characteristic of low-efficiency and high-pollution-emissions, which is one of the objects need to be focused on under the framework of environmental taxes. The cost of treatment varies from 2.62yuan/kg to 0.64yuan/kg in different industries, and the average cost of sewage treatment 1.74yuan/pollution equivalent. Furthermore, considering the tighter emission standards and higher treatment cost, this paper discusses the influence of environmental taxes on small and micro businesses under different tax rates (1.40,1.74,3.48,7.50yuan/pollution equivalent rate), proposes that small and micro businesses may withstand environmental taxes based on the pollution treatment cost, and an increase in the tax rate can significantly reduce pollution emission.