The invention relates to a mounting method of a steel chimney cylinder. In the mounting method of a steel chimney cylinder, the mounting of the steel chimney cylinder is carried out by two parts. The mounting method is characterized in that: (1) the elevation of the cylinder of a first part is Delta-4.5m- Delta-0.5m, an embedded central dial plate is used as a central point of the cylinder of thefirst part, and an auto crane of 16-25t is used for mounting; (2) the elevation of the cylinder of a second part is Delta-0.5m- Delta+70m, and the cylinder of the second part is mounted by three parts: the elevation of the cylinder of a first segment is Delta+36m- Delta+70m, the elevation of the cylinder of a second segment is Delta+11.5m- Delta+36m, and the elevation of the cylinder of a third segment is Delta-0.5- Delta+11.5; all sections of the cylinders of the cylinder segments are reversely mounted by adopting two sets of 10t fixed pulley blocks as a main hoisting system; and the cylinder of the third segment and the cylinder of the first part, the cylinders of the second segment and the third segment and the cylinders of the first segment and the second segment are all sequentially mounted by adopting two sets of 10t fixed pulley blocks as the main hoisting system. The mounting method has the characteristics of simple and convenient construction and low cost.