An adhesive promoter, an organic silicon encapsulant composition, and an organic silicon encapsulant are provided. The adhesive promoter used for the organic silicon encapsulant is formed from a borosiloxane polymer represented by a general formula of: (R1R22SiO1/2)x(R2R3SiO2/2)y(R3SiO3/2)z(SiO4/2)i(BO(3-k)/2)j(OR4)k. R1 is a hydrogen atom or a C2-C6 alkenyl group. R2 and R4 are respectively a C1-C6 alkyl group. R3 is a C6-C12 aromatic group. In the general formula, x, y, z, i, j, and k represent a molar ratio. In the general formula, x, y, z, i, and j are a non-negative number smaller than or equal to 1, and k is a positive number ≤3. A sum of x, y, z, and i is 1, and x is larger than 0.