The invention relates to a construction method of a suspended elevator shaft of a seismic isolation system. The construction method comprises the following steps that 1, after foundation slab construction is completed, a fine sand layer is laid at the bottom of an elevator foundation pit, and the coefficient of compaction is 0.94; 2, an extruded sheet with the thickness of 50 mm is placed on the fine sand layer; 3, another extruded sheets are arranged close to the two sides of the side wall of the elevator foundation pit respectively; 4, a concrete cushion layer with the thickness of 100 mm is poured, it is guaranteed that the cushion layer is disconnected from the side wall of the elevator foundation pit in the construction process, and the two sides of the elevator shaft structure are expanded by 100 mm; 5, the two sides of the elevator shaft structure expanded by the cushion layer are each provided with another extruded sheet with the thickness of 100 mm; 6, after construction of the suspended elevator shaft is completed and the strength of concrete meets design requirements, all the extruded sheets and the fine sand layer are taken out, and construction of the whole suspended elevator shaft is completed. The method is used for construction of the suspended elevator shaft with the elevator foundation pit at the bottom in a seismic isolation structure, the problem that in the construction process, bottom and side face supporting systems cannot be dismounted is successfully solved, meanwhile, cost is lowered, and the good application prospect is achieved.