The invention discloses an optimized-productivity production method of diketene. A 2# standby emergent cooler is used for always controlling the high-negative pressure production of a device system, and if the emergent cooling pressure difference reaches 3KPA or above, the standby emergent cooler is immediately switched online to ensure high-negative pressure and long-cycle production of the system; meanwhile, 96% of acetic acid entering an acetic acid evaporator is secondarily preheated so as to prolong the operating cycle of the evaporator; furthermore, a light anhydride pump intermittentlycirculates light anhydride for 4#-6# condensers, so that the problem of blockage of the condensers is solved, the cracking operating cycle is improved, and the yield of the diketene within the unit time is increased; meanwhile, the maintenance time is shortened, the effective production time is prolonged, and the maintenance cost and the production cost are reduced; meanwhile, production of pollutants and wastewater is reduced. An optimized-productivity and cycle-prolonged production technology and an optimized-productivity and cycle-prolonged production device of the diketene are provided.