Blasting construction method for small-clear-distance close existing tunnel

The invention provides a small-clear-distance close-connection existing tunnel blasting construction method which comprises the following steps that S1, shot holes are reasonably arranged in a tunnel to be blasted, the positions, the depth and the number of the shot holes are controlled, and the shot holes comprise cut holes, groove expanding holes, auxiliary holes, peripheral holes and bottom plate holes which are constructed; s2, electronic detonators and explosives are loaded into the shot holes; and S3, when the explosives are filled in a segmented and spaced mode, the cartridges are fixed through bamboo chips, each segment needs to be independently provided with an electronic detonator, miss-fire explosion is avoided, and the directions of the electronic detonators must be consistent with the explosion direction of the explosives. According to the method, the electronic detonators at different sections are adopted, segmented detonation is achieved, meanwhile, the purpose of reducing the blasting vibratio