The invention relates to a flushing system and a closestool. The flushing system comprises an explosion drain valve, a pilot device and a touch assembly, wherein the explosion drain valve is arranged in a water tank of the closestool and is provided with a water inlet and an outfall communicated with the water tank; the pilot device comprises a pilot valve connected with the water inlet, a running water communication assembly and an overflow assembly; the running water communication assembly and the overflow assembly are connected with the pilot valve; and the touch assembly is arranged on the water tank and electrically connected with the pilot valve. Due to the arrangement of the touch assembly, the pilot valve is controlled to provide the explosion drain valve with water through the touch assembly, the touch assembly is convenient to operate, the control function of the touch assembly can be achieved only by light touch, the operation is time-saving and labor-saving, the touch assembly is high in response speed, the operation time is greatly shortened and the operation efficiency is improved. Meanwhile, water entering from the water tank is discharged at powerful kinetic energy through the outfall under the action of the explosion drain valve, so that the flushing reaction rate and the flushing effect are improved and the water-saving effect is achieved.