The invention discloses a dacron FDY oiling agent and a preparation method thereof, and relates to the field of dacron spinning oiling agents. The dacron FDY oiling agent is composed of the followingcomponents of, in percentage by weight, 14%-33% of base oil, 24%-38% of a smoothing agent, 7%-11% of a bundling agent, 7%-11% of an emulsifier, 5%-7% of an antistatic agent, 1%-3% of a penetrant, andthe balance additives. According to the dacron FDY oiling agent and the preparation method thereof, through the selection and proportioning of monomers, the prepared FDY oiling agent has good comprehensive properties of smoothness, bundling, static electricity resistance, permeation, heat resistance, sizing and uniform adhesion, is good in spinnability, greatly reduces abnormal broken filaments, broken ends, white powder and tension fluctuation and winding phenomena, and can significantly improve the superior product rate under the same spinning process conditions. In the subsequent printing and dyeing process, dyeing is difficult, the phenomenon of uneven dyeing is reduced, and the fiber dyeing M rate is increased.