The invention relates to a high-precision surface evening method for large-sized high-bearing capability steel structure slideways, which includes the following steps that: a large-sized steel structure slideway is paved on a mounted slideway beam, and the evenness of the slideway is measured; according to the measured evenness, the slideway is precisely evened by blocking up the lower part of the slideway and partially pressing the upper part of the slideway; one end of a feed tube and one end of an exhaust tube are respectively inserted under both ends of the slideway, and the periphery of the lower part of the slideway is sealed by sealant; the other end of the feed tube is connected with an epoxy resin supply device, the epoxy resin supply device supplies epoxy resin into the lower part of the slideway via the feed tube, the exhaust tube is clamped by a tube clamp to prevent air leakage after the epoxy resin floods out of the exhaust tube, and after solidification, the evened state of the top surface of the slideway is kept. The invention has the advantages of low construction cost, high compression strength, high positioning precision, simple construction and the like.