The invention discloses a sugar orange container nursery substrate which comprises 40-50 parts of earthworm casts, 10-15 parts of vermiculite, 8-10 parts of perlite, 10-15 parts of molasses fermentation liquor, 3-5 parts of soot, 3-5 parts of luffa stem, 3-5 parts of fermentative strain, 20-30 parts of soft sediment with the moisture content of 90%, 15-20 parts of corncob cellulose, 3-5 parts of houttuynia cordata, 3-5 parts of cactus, 3-5 parts of watermelon peel, 3-5 parts of radix ophiopogonis, 3-5 parts of purslane, 3-5 parts of cucumis hystrix, 1-2 parts of fosamine and 10-20 parts of inorganic fertilizers. The invention also discloses a method for preparing the sugar orange container nursery substrate. The substrate disclosed by the invention is comprehensive in nutritional ingredient and balanced and coordinated in ratio, so that sugar oranges can obtain full and coordinated nutrition supply in the whole growth period, growth of the sugar oranges is effectively promoted, good quality of the sugar oranges is guaranteed, and the yield can be efficiently increased.