The invention discloses a cultivation and domestication method of activated sludge for difficultly biodegraded organic wastewater biological treatment. The method comprises the main steps of (1) mixing corn stalk fragments, low-concentration waste water and pig manure, and carrying out anaerobic fermentation in a cultivation pond; (2) after finishing fermentation, adjusting pH to 6 to 8, feeding activated sludge, and then carrying out anaerobic fermentation; (3) after flocculent hyphae appear on the surface of a mixture, transferring into a biochemical pond, adding flour, urea and a phosphatic fertilizer, and then feeding the waste water for domesticating the activated sludge; (4) when designed duty of water is reached and the effluent quality reaches the standard, accomplishing sludge domestication. The average removal rate of the activated sludge cultivated and domesticated by the method provided by the invention on waste water CODCr is 86 percent, and the effluent quality reaches the secondary standard of comprehensive wastewater discharge standard (GB8978-1996). The cultivation and domestication method of the activated sludge for difficultly biodegraded organic wastewater biological treatment provided by the invention solves the problem of difficultly biodegraded organic wastewater biological treatment difficulty, can be used for cultivating the activated sludge capable of high-efficiently treating the difficultly biodegraded organic wastewater, and utilizing pig manure and straw wastes at the same time, and is low-cost, and high efficient and stable.