The invention provides an oil removing agent for continuous processing of a terylene/spandex and chinlon/spandex blended knitted fabric and a preparation method of the oil removing agent. On the basisof the total weight of the oil removing agent for continuous processing of the terylene/spandex and chinlon/spandex blended knitted fabric, the oil removing agent comprises the following components in percentage by weight: 50-70% of a polyoxyalkylene nonionic surfactant, 2-15% of a chelating agent, 1-5% of a fluorocarbon surfactant, 0.2-3% of an organic fluorine finishing agent, 1-10% of an organic solvent, and 15-35% of water. The oil removing agent provided by the invention has high oil removal property, emulsification dispersibility, anti-staining property and fast permeability, and solvesvarious dyeing and finishing processing problems caused by poor oil removal in a continuous pretreatment process of the terylene/spandex or chinlon/spandex blended knitted fabric.