Polyaniline/Zinc oxide (PANI/ZnO) were prepared using a two-step method, and the morphology and the structure of PANI/ZnO composites were characterized through a scanning electron microscope (SEM) and X-ray diffraction (XRD). Factors such as the content of ZnO, the adsorption time and the mass of the adsorbent, and the kinetic equation of PANI/ZnO as adsorbents for the adsorption of methyl orange solution were studied. The results showed that the adsorption efficiency of methyl orange by polyaniline with the increase of adsorbent mass firstly increased and then decreased. Among the composites with the same quality, PANI composites with 8% ZnO have a better adsorption effect for methyl orange, and the maximum adsorption ratio can reach 69% with the increase of adsorption time at 0.033 g; With the increase of adsorbent mass, the adsorption efficiency of PANI composites with 8% ZnO increased continuously. When the mass increased from 0.033 g to 0.132 g, the adsorption rate increased from 69% to 93%, and the adsorption of the methyl orange solution by PANI/ZnO composites was more in line with the quasi-second-order kinetic equation.