The invention discloses heat-insulating, waterproof and environment-friendly paint and a preparation method thereof. The heat-insulating, waterproof and environment-friendly paint is prepared by adding a porous inorganic material into acrylic emulsion, and combining pigments, auxiliaries and a lotus effect self-cleaning agent. The heat-insulating, waterproof and environment-friendly paint has very good solar reflecting ability and extensibility, has a reflecting rate of 86% on sunlight, has radiance of 0.88, has absorbing ability of 99.9% on ultraviolet light, and can effectively inhibit the temperature of a coated object from quickly increasing under the irradiation of sunshine. In hot summer, the heat-insulating, waterproof and environment-friendly paint can effectively isolate solar radiant heat, so that the working time of an air conditioner is reduced, and energy resources are saved. Besides, the solid content of the paint exceeds 65%, and the paint is high in covering power, has good extensibility and waterproof function, and is guaranteed to be not cracked while used on the surface of an object with fierce temperature variation and obvious expansion and concentration, so that good waterproof rust-proof protection is provided for equipment, a pipeline, a storage tank and the like. The paint is rich in color and long in service life, and not only provides a remarkable energy-saving effect, but also achieves the effect of beautifying a building.