The invention discloses an anti-crack waterproof self-healing film outer wall external heat insulation system and a preparing method thereof. A heat insulation layer is of a multi-layer structure, and an inner self-healing film layer, a modified inorganic heat insulation mortar layer, a polymer anti-crack mortar layer and a veneer layer which are closely attached in sequence are arranged from inside to outside. An alkali-resisting gridding cloth layer and an outer self-healing film layer are sandwiched in the polymer anti-crack mortar layer. The outer self-healing film layer is arranged on the outer side of the alkali-resisting gridding cloth layer. A self-healing film comprises activated silica modified acrylic resin, silica modified ethylene-vinyl acetate resin, dibutyl phthalate, an alkali activator, active fumed silica, waterborne additives, water and the like. The invention further discloses the preparing method of the anti-crack waterproof self-healing film outer wall external heat insulation system. According to the anti-crack waterproof self-healing film outer wall external heat insulation system and the preparing method thereof provided by the invention, the functions of water resistance and heat insulation are integrated, the anti-crack performance of the system can be greatly improved, and the problem that inorganic heat insulation mortar is prone to sucking water at present is solved.