The invention discloses photocatalytic nanometer spray coating and a method for preparing the same, and belongs to the technical field of photocatalytic coating. The photocatalytic nanometer spray coating comprises, by weight, 48.5%-49.5% of asphalt, 50%-51% of liquid soap and 0.5%-1% of silane coupling agents. The sum of the mass percents of the asphalt, the liquid soap and the silane coupling agents is a hundred percent; the liquid soap comprises, by weight, 0.4%-2% of stabilizers, 3%-6% of emulsifiers, 2%-6% of dispersing agents, 10%-20% of nanometer TiO2 and the balance high-purity water, and the sum of the mass percents of various components of the liquid soap is a hundred percent; the mass of the dispersing agents accounts for 20%-30% of that of the nanometer TiO2. The photocatalytic nanometer spray coating and the method have the advantage that problems that road spray coating is poor in storage stability, colors of the road spray coating are greatly different from colors of asphalt pavements, the antislip and permeability performance of the pavements are deteriorated and the driving safety is affected in the prior art can be solved by the aid of the photocatalytic nanometer spray coating and the method.