As we all know, the methylene blue and basic fuchsin in the printing and dyeing wastewater are harmful to the human body. In this work, Fe3O4@SA/Ca adsorbents were prepared with sodium alginate as the skeleton, and Fe3O4 was combined with chitosan and CaCl2 as the cross-linking agent to remove these two pollutants. A series of microscopic characterizations of the prepared materials were carried out, such as XRD, SEM, FT-IR, VSM, etc. The effects of single factors such as pH, adsorbent dosage, reaction time, and initial concentration of substrate on the adsorption process were considered. The isotherm model and kinetic equation model were established to study the adsorption mechanism. The adsorption of methylene blue and basic fuchsin by the adsorbent at different pH was studied. Finally, the adsorption performance of the adsorbent for methylene blue or basic fuchsin for five consecutive times was investigated. The results showed that the material was successfully prepared, and the appearance was wrinkled. There were a large number of oxygen-containing functional groups on the surface of the molecular structure, and the material had strong magnetic properties. When the initial concentration of methylene blue or basic fuchsin was 100 mg/L, the dosage of adsorbent was 1.0 g/L, the pH of methylene blue was 11 or the pH of basic fuchsin was 8, and the reaction time was 4 h, the removal rate of the two kinds of pollutants by the material could reach 91.9% and 21.5%, respectively. It was obvious that the adsorption of methylene blue by the adsorbent was stronger than the adsorption of basic fuchsin. The fitting results showed that the Langmuir model can better reflect the adsorption of methylene blue or basic fuchsin, and the adsorption was dominated by a single-layer surface covering. The adsorption kinetics conforms to the pseudo-second-order kinetic equation, and the adsorption process was more susceptible to chemical adsorption. When the pH=9, the adsorption capacity for methylene blue was 82.6 mg/g, and the adsorption capacity for basic fuchsin was 36.6 mg/g. Five consecutive desorption and regeneration experiments proved that the Fe3O4@SA/CTS adsorbent was desorbed and regenerated under 0.1 mol of HCl, and it has good reusability.