The invention provides an all-solid-waste cementing material synergistically prepared from steel slag and a multi-objective optimization method, and relates to the technical field of mine field filling; large-scale and high-added-value resource utilization of steel slag and industrial byproduct gypsum low-quality solid waste in filling mining can be realized, so that the tailing filling mining cost is reduced, and the economic benefit and the environmental protection benefit of filling mining are improved. The method comprises the steps: preparing the all-solid-waste cementing material from the steel slag, industrial by-product gypsum and mineral slag, filling by taking mine superfine full tailings as aggregate, and establishing a multi-objective optimization model by taking the strength cost performance of a filling body, the cost of the filling material and the utilization rate of the mineral slag as optimization objectives and taking the strength and the volume expansion rate of thefilling body as constraint conditions; and according to the multi-objective optimization model, obtaining the optimal proportion of the components in the all-solid-waste cementing material. The method provided by the invention is suitable for a mine field filling process.