The invention discloses a shock absorption protecting system for hard rock subway station excavation through a middle hole method. The shock absorption protecting system for hard rock subway station excavation through the middle hole method comprises polystyrene boards laid on side walls and an inverted arch; the polystyrene boards are provided with concrete layers, and during excavation of neighboring chambers, blasting buffer rock walls as thick as 0.8-1 m are preformed in the side walls and the inverted arch. The invention also discloses a construction method of the shock absorption protecting system for hard rock subway station excavation through the middle hole method comprises digging a middle hole at a depth of 10-15 cm exceeding the side walls of the middle hole and 15-20 cm exceeding the inverted arch of the middle hole; laying the polystyrene boards onto the rock surfaces of the side walls and the inverted arch and setting the concrete layers for leveling to form the isolation buffer structure of a temporary support; mounting the temporary support; after first-layer safe steps meet requirements, preforming 0.8-1.0 m thick rock walls at the top of a second layer and then performing blasting processes; during excavation of a side hole, preforming 0.8-1.0 m thick rock walls in a middle separating wall and then performing blasting processes. By arranging the polystyrene boards and the concrete layers on the side walls and the inverted arch and preforming blasting buffer rock walls during excavation of neighboring chambers, the shock absorption protecting system for hard rock subway station excavation through the middle hole method can reduce damage of shock to the temporary support to the maximum degree and ensures construction safety.