The invention relates to a surface micro-coating agent for producing pure paper and non-woven paper. The surface micro-coating agent comprises the following components: 1.25 percent to 2.5 percent of modified polyethylene emulsion with the mass concentration of 30 percent, 10 percent to 20 percent of acrylic resin with the mass concentration of 30 percent, 10 percent to 20 percent of softener with the mass concentration of 30 percent, 0.001 percent to 0.01 percent of coupling agent with the mass concentration of 30 percent, 0.001 percent to 0.01 percent of water-resistant agent with the mass concentration of 100 percent, 0.01 percent to 0.02 percent of penetrating agent with the mass concentration of 30 percent, 0.1 percent to 0.2 percent of anionic emulsifier with the mass concentration of 100 percent, a thickener of which the adding quantity ensures the viscosity of the coating agent in the range of 19 to 25s, and the balance of water. The invention also provides a preparation method of the surface micro-coating agent. According to the invention, conventional modes of adding the softener into pulp and coating with styrene-butadiene latex and oxidized starch are not adopted; and the performances, such as the tensile strength, the surface strength, the softness and the water resistance, of paper can be simultaneously improved just by adopting the surface micro-coating agent to carry out one-step coating.