The utility model discloses a flexible cable tray of bypass, including the fashioned isolated trench box of the special section bar integral type of adoption slot type strenghthened type, and with isolated trench box phase -match, and can with the plug -type insulating apron that opens and shuts of isolated trench box, still including lieing in isolated trench box bottom portion, and be used for the isolated trench box fixed bolster of fixed isolated trench box. The utility model discloses a scheme can overcome that operation process is complicated among the prior art, the engineering time is long and adaptability to changes subalternation defect to realize that operation process is simple, the engineering time short and the advantage of strong adaptability.