Protective coating structure for building outer wall

The utility model relates to the field of building outer wall coatings, and discloses a protective coating structure for a building outer wall. Comprising an outer wall body, a cement mortar layer is arranged on the outer wall body, the cement mortar layer is of a wave-shaped structure, the cement mortar layer is coated with an adhesive layer, a high-weather-resistance layer is arranged on the adhesive layer, and an anti-crack protection layer is arranged on the high-weather-resistance layer. And an antifouling protection layer made of a silicon dioxide-polydimethylsiloxane material is arranged on the anti-crack protection layer. And through the arrangement of the anti-crack protection layer, the strength of the coating is enhanced, cracking and separation caused by long-time use are avoided, and the stability of the wall is improved. Through the arrangement of the antifouling protection layer, the wall body has super-strong hydrophobicity, dirt on the wall body is washed by rainwater to be clean, the self-cl