The utility model provides a water -storage uses in power station overhaul of equipments cat ladder, it is main includes body, footboard, motor, haulage rope, still include with the body through bolted connection and restrict the footboard along the body surface do the vertical motion the limiting plate, pass through spring coupling and restrict footboard in fixed position's positioning mechanismwith the body, the gyro wheel in footboard four corners sets up in the open slot that the body upper surface was seted up, the motor passes through the haulage rope and is connected with the footboard, positioning mechanism include the spring, with spring upper end fixed connection's sliding wedge piece, the distribution be connected with the sliding wedge piece surperficial fixed connection's inthe outside slide bar, with a plurality of slide bar in body both sides respectively by two rectangular traces of constituteing of parallel metal, include still that the both ends tip cup joints keeping away from the U type actuating lever of body side. The utility model relates to an automatic cat ladder has been solved current ladder and has been relied on the user to scramble the operation, andthe instrument of carrying causes the inconvenient problem that easily produces the potential safety hazard of climbing.