The invention provides a composite binder for an iron ore pellet as well as a preparation method and application method thereof and belongs to the technical field of pellet production. The composite binder for the iron ore pellet comprises the following components in percentage by mass: 5-40% of starch ether, 5-20% of cellulose ether, 5-20% of guar gum and 50-70% of calcium carbonate, wherein the particle size of calcium carbonate is 0.02-1.0 micronmeter, and the particle sizes of other raw materials are respectively less than 100 meshes. The preparation method comprises the following steps of: weighing the raw materials in ratio, and uniformly mixing, so that the composite binder for the iron ore pellet is obtained. The application method comprises the following steps of: directly adding into iron ore concentrate or uniformly dispersing into water to obtain uniform slurry and then adding into the iron ore concentrate, uniformly mixing, pelletizing, and roasting, so that an iron ore oxidized pellet is obtained. The obtained composite binder has good binding property, low usage amount and less residue and can be used for improving the roasting ball strength, grade of the iron ore pellet and ironmaking economic benefit when applied to preparation of the iron ore pellet.