The invention relates to a method for fruiting bag-cultivated mushroom at one time. The method comprises the operation steps of mushroom selection, inoculated culture, test tube expanding, cultivated species inoculation, cultivated species culture, strain treatment, raw material pretreatment, material batching and stirring, mushroom stick packaging, mushroom stick sterilization, mushroom stick inoculation, mushroom stick cultivation, mushroom stick coloring, mushroom stick pretreatment and mushroom stick fruiting. Coarse and fine culture base materials of a mushroom stick produced by utilizing the scheme are reasonably matched, nutrient substances are full, and perlite in a formula has the functions of holding moisture, ventilating air, regulating the potential of hydrogen and providing multiple microelements needed by the growth of the mushroom; meanwhile, oak chips and apple chips are mixed with corncobs, so that the ventilation of the mushroom stick is improved, the biotransformation rate of the mushroom is improved favorably, biotransformation of the mushroom stick can be promoted by virtue of a great number of microelements in canal mud, the uniformity of mushroom stick fruiting is improved by pre-cooling a mushroom bag, the mushroom stick fruiting speed is increased by utilizing the stimulation of the difference between pre-cooling temperature and external environment temperature, and the biotransformation rate is improved by 10-20 percent.