A novel magnetic anticancer drug carrier based on cellulose, guar gum, and Fe3O4 hydrogel microspheres was synthesized by chemical crosslinking. These microspheres were crosslinked with epoxy chloropropane and loaded with 5-fluorouracil (5-fu). The effect of the ratio of cellulose to guar gum on bead size, drug loading, and in vitro release behaviors were investigated. The influence of the magnetic content on drug loading and in vitro release behaviors were also evaluated. The magnetic hydrogel microspheres were characterized via an optical microscope, Fourier transform infrared spectroscopy, swelling behavior analysis, vibrating sample magnetometer, and ultraviolet absorption spectroscopy. The results showed that as the ratio of cellulose to guar gum increased from 3:1 to 5:1, the particle size increased from 395 to 459 um. Moreover, the drug loading capacity, encapsulation efficiency, and in vitro release behavior were influenced by the ratio of cellulose/guar gum and Fe3O4 content. Finally, the Fe3O4 particle had an adsorption effect on the drug, thereby reducing the maximum cumulative release.