The invention discloses an iodine citrate foam-type disinfectant and a preparation method thereof. The iodine citrate foam-type disinfectant consists of the following components: 5 to 50 weight percent of citric acid, 0.5 to 5 weight percent of iodine, 0 to 20 weight percent of potassium iodide, 0 to 20 weight percent of potassium iodate, 0.1 to 10 weight percent of a foaming agent and 0 to 10 weight percent of a foam stabilizing agent, and the balance of a solvent, wherein the solvent consists of water and an organic solvent. The preparation method comprises the following steps: 1) dissolving the citric acid in part of water to obtain a solution I, and dissolving the iodine, the potassium iodide and the potassium iodate in the rest water to obtain a solution II; 2) mixing the solution I and the solution II in the step (1) to obtain a solution III; 3) adding the foaming agent and the foam stabilizing agent into the solution III obtained in the step 2), and adding the organic solvent. The disinfectant is long in half-life period and good in disinfection effect.