The invention provides a rubber ball collecting device of a power plant condenser. The device comprises a ball collecting pipe and a sealing door; a cleaning port is a rectangular port, and is formedin the front side surface of a shell as an observation window for examining and maintaining parts in the shell; the same position on the outer wall of the shell is connected with a sealing door through a hinge for tightly closing the cleaning port; second fixed blocks and first fixed blocks are the same in structure; six second fixed blocks and six first fixed blocks are provided; three second fixed blocks and three first fixed blocks are arranged on the bottom side of each inclined plate, and are distributed at equal intervals; water currents fed from a water inlet can be collected and adjusted through the inclined plates; the inclination of the inclined plates is adjusted through adjusting rods to achieve a guide effect on the water currents and to reduce downward impulsive force of thewater currents; downward water passes through a flow breakage roller to push rubber balls to rotate to cut off the water currents; and downward force is weakened again, so that the strength of the water currents and the rubber balls reaching a ball collecting net is lower, higher impact on the ball collecting net is prevented, and meanwhile, the surfaces of the rubber balls are not easy to wear.