The invention discloses a surge shaft construction method combining impedance with overflow, which includes that the height of a surge shaft body is determined based on
reservoir water level and subjected to be higher than exceptional flood level, the inner
diameter D of the shaft body is determined based on stable section area calculated by Thoma criterion, and the thickness of the shaft body wall is determined based on the meeting of concrete anti-crack requirements and axis force bearing requirements; the mouth edge at the top of the surge shaft is made into an arc-shaped overflow weir; an annular stilling
pool is constructed around the surge shaft body, the width of the stilling
pool is determined according to the nappe length Ld of falling water during the overflow of the surge shaft, the altitude of the stilling
pool bottom is the altitude of complete
bedrock, and lining protection is performed according to the depth of water in the stilling pool; a sluiceway communicated with the stilling pool is constructed on one side of the stilling pool, and the bottom of the stilling pool is excavated to the
bedrock surface; a connecting
pipe communicated with a water drawing dynamoelectric tunnel is excavated perpendicularly downwards at the bottom of the surge shaft, and consolidation grouting is performed on the periphery; and the
diameter of the connecting
pipe is determined based on the requirement of an impedance hole. The surge shaft construction method has the advantages that the structure is simple and compact, the project amount is small, and the investment is saved.