The invention discloses a mechanical demolition construction method of a cooling tower. The mechanical demolition construction method comprises the following steps that in the process of mechanical demolition construction operation, the collapse center line is selected firstly, the position of a collapsed buffer wall column is determined according to the collapse center line, then the load-bearingparts of the tower wall are gradually destroyed on the two sides of the collapse center line, notches are enlarged, the weight of the cooling tower is forced to press to the buffer wall column in theprocess of gradual enlarging of the notches, when cracks occur on the buffer wall column and the notches in the two sides of the buffer wall column, mechanical equipment is removed and demolished immediately, and the cooling tower collapses automatically in the predetermined direction under the self weight of the cooling tower; site inspecting is conducted after the cooling tower collapses, and acollapsed tower body is crushed and waste and old materials are recycled after dangers are eliminated; a foundation is excavated and crushed; and acceptance check work is conducted. The mechanical demolition construction method of the cooling tower effectively controls collapse-to-ground vibration, construction is fast, and the safety factor is high.