The invention discloses a composite 
supporting system for a 
coal mine rectangular gate roadway during pressure bump based on the strong-releasing and strong-supporting theory. The composite supportingsystem comprises a roof 
supporting system used for supporting a gate roadway roof, a side 
supporting system used for supporting the two sides of the gate roadway and a pressure-releasing groove formed in a floor of the gate roadway. The roof supporting 
system comprises a plurality of roof short anchor cables and 
energy absorption pieces; every two adjacent roof short anchor cables extending in the length direction of the gate roadway are connected through roof U-shaped channel steel, and roof pressure-releasing holes are formed in the roof; the side supporting 
system comprises a plurality ofside short anchor cables and 
energy absorption pieces; and every two adjacent side short anchor cables arranged in the height direction of the sides are connected through side U-shaped channel steel,and side pressure-releasing holes are formed in the two sides of the gate roadway correspondingly. The composite supporting 
system adopts the principles of strong-releasing and strong-supporting as well as shock absorption and 
energy absorption, overall deformation of the roadway can be effectively restrained, harm to personnel and equipment can be reduced when pressure bump occurs, and meanwhilefloor heave of the roadway is effectively restrained.