To provide a combined structure of two-wire side racks and shelf members of a collapsible rack.

At least two two-wire side racks and at least two shelf members are included, the shelf member has locking means for stretching and opening the front and rear columns of the two-wire side rack at four corners, and movable locking means are fitted respectively to the left end and right end of steel wires at the front end and rear end. By combining the shelf member with the right and left two-wire side racks and then installing the movable locking means for the locking means, a sideward support action is generated between the shelf member and the two-wire side rack, connection strength between the shelf material and the two-wire side rack is increased, and thus the collapsible rack after being assembled is prevented from being shaken to the right and left by external force.