The invention discloses a modification device of special calcium-based powder for an adhesive. The modification device comprises a grinding machine and a kneading machine connected with the grinding machine, and further comprises a mixing device arranged between the grinding machine and the kneading machine, wherein the mixing device comprises a mixing chamber, a modifier spraying pipe, a hot high-pressure gas spraying pipe and a powder spraying pipe, the powder spraying pipe is located on the upper portion of the mixing chamber, and one end of the powder spraying pipe extends into the mixingchamber. The invention further discloses a modification method of special calcium-based powder for an adhesive, wherein the method comprises: modifying by using the modification device. According to the invention, the modifier and the powder are mixed before kneading, so the modifier on the surface of the powder can be uniform while the adhesion rate of the modifier on the powder surface is guaranteed; and the powder enters the kneading machine and is subjected to kneading modification after being fully attached with the modifier, so the quality of the powder is guaranteed, the activation degree of the powder can be effectively improved, the process is simple, and the activation degree of the modified powder is larger than 90%.