The invention discloses a harvesting and processing method of Carya illinoensis. The method includes the following steps that an ethephon preparation with concentration of 200 mg/kg is sprayed to bearing branches for one time four weeks before harvesting of the Carya illinoensis, and Ca(OH)2 is used for adjusting a power of hydrogen (PH) value to be 7.0; when the ethephon preparation is sprayed for two weeks and 70% of fruit episperm is cracked, the Carya illinoensis is harvested; deadwood and sundries under trees are cleared away, and a black mesh fabric is spread; a machine shakes the bearing branches, fruits falling on the mesh fabric are timely collected, sundries are removed, episperm which is not cracked is removed in a huller, and the fruits are washed by running water; and rinsing, ozone disinfection and drying with a drying machine are performed so that moisture contents of the fruits are lower than 4.3%, and storage is finally performed. By means of the harvesting and processing method, fruit maturity periods of the Carya illinoensis can be unified, natural fruit drop is reduced, a launch date of the fruits is shifted to be earlier, output is improved, fruit cracking and fruit color changing caused by solarization are avoided, and qualities of the fruits are improved so that selling prices of the Carya illinoensis are effectively increased.