The utility model discloses an assembled cat ladder, including ladder beam subassembly and running -board subassembly, the ladder beam subassembly includes two piece at least ladder beam, and the running -board subassembly includes a plurality of parallel arrangement's running -board, and the running -board is located between two adjacent ladder beam, the last first mounting hole of multiunit that is equipped with of ladder beam, first mounting hole on two adjacent ladder beam symmetry sets up, ladder beam's both ends are equipped with the fixed orifices, the both sides of running -board are equipped with the mounting panel, be equipped with on the mounting panel with the second mounting hole of first mounting hole adaptation, first mounting hole and second mounting hole pass through bolt and nut connection. The utility model provides a pair of assembled cat ladder adopts modular structure, adopts on -site Assembly during the use, and its space that occupies is less, convenient storage transportation, and the installation is simple swift, need not welded fastening, can realize quick assembly disassembly, and overall structure is stable.