Abstract: In order to explore the influence of oxidants on the fractal characteristics of coal pores, samples of low-rank coal from Qianqiu Mine, medium-rank coal from Shaqu Mine and high-rank coal from Zhongma Mine were collected, and coal samples of different coal ranks were pretreated with chlorine dioxide and ammonium persulfate. The pore structure of coal samples before and after oxidant treatment was analyzed, and the pore fractal dimension was calculated. At the same time, the relationship between fractal dimension and tortuosity and porosity was analyzed. The results show that as the coal rank increases, the pore fractal dimension gradually decreases; after treatment with oxidant, the coal sample pore fractal dimension, tortuosity and porosity all increase in different degrees, indicating that the oxidant can increase the complexity of coal pores. At the same time, it is conducive to the desorption and transport of coalbed methane, and the promotion effect of chlorine dioxide is more obvious than that of ammonium persulfate; as the pore fractal dimension increases, the tortuosity decreases first and then increases. The pore fractal dimension D=2.80 is approximate the turning point of the trend line, and the porosity shows a downward trend.