The invention relates to the technical field of biomedical engineering, in particular to hydrogel for treating diabetic foot and a preparation method of the hydrogel. The hydrogel comprises the following components in percentage by mass: 0.1%-20% of microspheres; and 0.5%-40% of a microcapsule. The microspheres are of a core-shell structure, components of an inner core of the core-shell structure comprise growth factors, components of the microcapsules comprise an accelerant, and the accelerant comprises beeswax and/or olive oil. The biological activity of the growth factor can be kept for a long time, the growth factor can release the combination effect of the microcapsules and the microspheres for a long time through the slow diffusion effect and the slow degradation of the microsphere carrier, and the effects of oxidation resistance, high temperature resistance, easiness in addition and compounding and no precipitation can be achieved.