The invention discloses a process for material returning and ash discharging of a fluidized bed boiler. After ash discharging of a loop seal is completed, ash cooling is started, an ash discharging pipe is a water cooling jacket tube, and a cooling water pipe which is connected with a cooling water main pipe is arranged between the inner layer and the outer layer of the water cooling jacket pipe;cooling water enters the cooling water pipe from the bottom of the water cooling jacket pipe through the main pipe and then enters a buffer tank for containing the loop seal through the cooling waterpipe; and the ash discharging pipe is inserted into the buffer tank to prevent the loop seat subjected to heat expansion from being blocked. According to the process of material returning and ash discharging, the boiler thermal efficiency can be improved, the slag discharge amount of a hearth is reduced, the probability that large-particle unfired coal is directly discharged from a slag dischargepipe can be reduced, and the safe and economical operation of the boiler can be guaranteed; an ash cooler is installed so that the bed temperature and the efficiency of the boiler can be improved, andthe safety coefficient of manual ash discharging can be improved; by adjusting the rotating speed of the ash cooler is adjusted, the differential pressure of the hearth is controlled to be 1400Pa, the bed temperature is stabilized, four workers are reduced, if each worker is provided with 5000 yuan each month, and the manual cost can be reduced by 20 thousand yuan per month; and the secondary pollution of on-site dust is avoided, and the operation efficiency of the boiler is improved.