The utility model discloses a collapsible flexible cable support comprises first, second, third subassembly, hinge jaw and bolt, first subassembly is a vertical steel sheet, the second subassembly is the crossbeam of U -shaped for the section, and carry out the pin joint through picking up the ears on hinge jaw and the first subassembly and be connected, the third subassembly is the crossbeam of U -shaped for the section, and third subassembly cover is put inside the second subassembly, and fastens through the bolt between the second, third subassembly, the second subassembly can rotate around the hinge jaw to have two kinds of limit state, state firstly second subassembly is in the horizontality, and secondly the state is in vertical state. Can fold one side cable support for opposite side cable laying increase construction space earlier when both sides all set up the cable support in the cable pit, can set up cable mount wide according to this issue of engineering cable reasonable quantity simultaneously, extend the cable support completely again during construction at a specified future date, it is nimble reliable.