The invention relates to a mechanical replacement and laying construction method for a
ballast turnout. The method comprises the steps of selecting a turnout pre-laying position, transporting the turnout, replacing and laying the turnout within blocking time, treating new and old stone ballasts,
welding the turnout and the like. According to the method, the whole set of turnouts are pre-laid outside the blocking time, and the method is implemented within the blocking time as follows: the whole set of turnouts are transported to the vicinity of a turnout replacing and laying area by adopting turnout replacing and laying equipment, old turnouts are dismantled and moved away,
ballast beds are excavated, old stone ballasts are removed and transferred, the
ballast beds are leveled, new turnouts are laid, tamping and stabilizing are performed, the turnouts are finely adjusted, and finally turnout
welding is completed until a line is opened. According to the invention, the turnout changing and paving quality is improved, the overall construction time is saved, the blocking construction frequency is reduced, the construction can be flexibly carried out according to the blocking time, the
mechanization degree is improved, the construction
safety risk and the labor intensity are reduced, meanwhile, the material and manpower consumption is reduced, and the cost is saved for the turnout changing and paving construction.