The invention discloses a solvent-free type organosilicone coating adhesive and a preparation method thereof. The organosilicone coating adhesive is prepared from, by mass, 70-100 parts of hydroxyl end-blocked dimethylsiloxane, 10-30 parts of adhesive film enhancer, 2-6 parts of cross-linking agent, 0.1-0.8 part of catalyst and 0.5-1.5 parts of tackifier. The preparation method of the solvent-free type organosilicone coating adhesive includes the following steps that hydroxyl end-blocked dimethylsiloxane and the adhesive film enhancer are added into a reaction still and stirred and mixed to be uniform under the vacuum condition, the cross-linking agent, the catalyst and the tackifier are added, and the mixture is stirred and mixed to be uniform under the vacuum condition. When the organosilicone coating adhesive is used, no organic solvent is needed for dilution, safety and environment friendliness are achieved, the compactness of cured adhesive film is high, and good high and low temperature resistance, insulating performance, binding performance, dampness resistance, earthquake resistance and corona resistance are achieved; the production process of the organosilicone coating adhesive is simple, the production cost is low, and the product is easy to construct.