Soft soil underground excavation tunnel underground engineering equipment and construction method

The invention relates to the technical field of tunnel engineering, in particular to soft soil underground excavation tunnel underground engineering equipment and a construction method.The soft soil underground excavation tunnel underground engineering equipment comprises steel arches, connecting plates are arranged at the two ends of each steel arch respectively, each connecting plate is provided with at least four through holes, and every two adjacent steel arches are connected through bolts and nuts; fixing barrels are fixed to the upper portion and the lower portion of the inner side face of the arc-shaped guide plate, contraction plates are slidably connected into the fixing barrels through hydraulic cylinders, rotating rollers are rotationally arranged on the end faces of the contraction plates through rotating shafts, the rotating rollers which are vertically symmetrical make rotating contact with the inner ring face of the steel arch, a motor is fixed to one side face of each contraction plate, and an