This article systematically compares and studies the sensitivity, accuracy, reliability, and practicality of four methods for characterizing the toxic effects of pollutants on microorganisms, including Microbial Toxicity Microtox (MTX), Microbial Respiration Rate (BOD), Microbial Dehydrogenase Activity (TTC), and Microbial Degradation Dynamics (DKT). The research results indicate that the Microtox (MTX) method can effectively reflect the microbial toxicity of pollutants, and it is easy to operate, time-consuming, and convenient for data interpretation. This method can be applied to evaluate the toxicity of natural water bodies and the toxic effects of pollutant biodegradation.