The invention discloses a large-section tunnel circular blasting and tunnelling method. The large-section tunnel circular blasting and tunnelling method comprises the following steps that a segment of guiding tunnel is tunnelled in the middle of the bottom end of the tunnel face of a large-section tunnel in the extension direction of the large-section tunnel; guiding holes are punched in a plurality of cross sections of the guiding tunnel according to a certain depth in the radial direction, and the guiding holes are distributed in a fan shape along the guiding tunnel; a plurality of large-section perimeter holes are punched in edges of fan-shaped outlines formed by the distribution of the multiple guiding holes in the axial direction of the guiding tunnel; after the guiding holes and the large-section perimeter holes are detonated, a segment of the large-section tunnel is formed, a passage is shovelled out in the middle of the large-section tunnel, and the waste stones detonated and caved are shovelled to the two sides of the passage to be used for paving steps; and the segmented and circular construction is performed until the tunnelling work of the whole large-section tunnel is accomplished. By means of the large-section tunnel circular blasting and tunnelling method, the circular operation of large-section tunnel blasting and tunnelling is achieved, the tunnelling efficiency is improved, the vibration of blasting is greatly reduced, the safety of the tunnel construction is improved, the requirements for the drilling equipment are lowered, the working strength of the staff is lowered, and the drilling work efficiency is improved.