Construction method for long and narrow crack renovation

The invention provides a construction method for long and narrow crack renovation, and relates to the field of construction. The construction method comprises the steps that a roadbed is detected, the position of a long and narrow crack in the roadbed is determined, and the width of the long and narrow crack is smaller than a preset threshold value; constructing a first through hole according to the position of the long and narrow crack; a grouting assembly extends into the long and narrow crack from the first through hole, and slurry is injected into the long and narrow crack till the top space of the long and narrow crack is filled with the slurry; the top space is located at the top of the long and narrow crack, and the distance between the top space and the roadbed top face is smaller than a preset threshold value. According to the construction method, the amount of the slurry needing to be filled can be reduced, and the filled slurry does not influence underground water in the deep layer of the roadbed,