Diversion construction method of wide-riverbed dam type hydropower station

The invention relates to a diversion construction method of a wide-riverbed dam type hydropower station, aiming at providing a diversion construction method of the wide-riverbed dam type hydropower station for shortening the total time limit of hydraulic power station engineering. According to the technical scheme provided by the invention, the method comprises the following steps: a, firstly building a diversion building on one side of a riverway; b, while building the diversion building, carrying out temporary cofferdam construction on a riverbed on the other side of the riverway; c, after the temporary cofferdam construction is finished, surrounding a foundation pit by a temporary cofferdam and riversides for discharging water, and carrying out construction on a large dam; d, after the diversion building has overflowing conditions, extending the upper reach and the lower reach of the temporary cofferdam to the other side of the riverway so as to form an upper reach main cofferdam and a lower reach main cofferdam; e, discharging water in the foundation pit between the upper reach main cofferdam and the lower reach main cofferdam to form a dry construction environment; and f, carrying out full-scale construction of the large dam or a factory building between the upper reach main cofferdam and the lower reach main cofferdam. The diversion construction method is suitable for the pivotal arrangement design and construction of the arrangement in a stage diversion manner adopted by the wide-riverbed dam type hydropower station.