Degreasing agent for avoiding bonding of cold rolled sheet steel in cover annealing and using method of degreasing agent

The invention discloses a degreasing agent for avoiding bonding of cold rolled sheet steel in cover annealing and a using method of the degreasing agent. The degreasing agent comprises the following components in percentage by weight: 20% to 25% of sodium hydroxide, 64% to 70% of positive sodium silicate, 3% to 5% of sodium carbonate, 5% to 10% of trisodium phosphate, 0.3% to 1% of nonionic surfactant and 0.1% to 0.5% of defoaming agent. The degreasing agent disclosed by the invention can be used for thoroughly cleaning various greasy dirt adhered to the surface of the cold rolled sheet steel and reserving a silicate membrane with proper thickness on the surface of the sheet steel so as to effectively avoid the bonding of the sheet steel in the cover annealing; and the membrane has on influence on properties such as the binding force of a coating, the processing of a steel plate, and the like. In addition, when the degreasing agent disclosed by the invention is used, the steel plate does not need to be immersed in the degreasing agent in advance, the modern quick unit degreasing can be implemented, the speed reaches 300m/min to 400m/min or above, and the degreasing is efficient and quick, so that the greasing agent is completely suitable for a modern quick unit coil degreasing line.