A manual pressing device for a flusher includes a stop ring, a pressing rod unit, a spring, and a nut. The manual-pressing device is located in a lateral hole of the body of a flusher, normally stopping water in the flusher or pressed to connect a lengthwise hole in the body with a water-exhausting passageway for flushing water. The nut screws with the body to keep the stop ring, the pressing rod unit and the spring stably combined in the lateral hole. When the pressing member of the pressing rod unit fitted with an outer end of the pressing rod is pressed inward, the annular leak recess of the pressing rod unit may communicate with the water exhausting passageway to let water flow therethrough so as to flush water, and releasing the pressing member pressed makes the pressing rod return to its original position to block the water exhausting passageway.