The total discharge of Chinese industrial wastewater is large, and the various organic pollutants contained in wastewater have always been a potential threat to human health. Therefore, it is necessary to develop various technologies for wastewater treatment, especially to study the degradation mechanism of organic pollutants. This paper summarizes the research methods for the degradation mechanism of various organic pollutants in wastewater, including experimental methods and computational simulations. In the experiments, spectral analysis techniques are mainly used to detect the intermediates produced during the degradation of organic pollutants, and then the degradation pathways of organic pollutants are deduced. However, due to the different experimental conditions and experimental methods, the degradation pathways of the same pollutant obtained from the different experiments are controversial. Computational simulations, based on the quantum chemical calculation, quantitative structure-activity relationship model, quantitative structure-biodegradation relationship model and statistical molecular fragmentation model, provide a new method for studying the degradation mechanism of organic pollutants. The combination of experimental methods and computational simulations will provide the foundation and guidance for exploring the degradation mechanism of organic pollutants.