The invention discloses a method for cultivating grain-feed corn, which comprises the following steps of: selecting a grain corn variety, selecting a land and preparing the land; the method comprises the following steps: selecting corn seeds, ridging and earthing, performing single-grain precision seeding in a suitable seeding period from May 5th to May 15th, and seeding selected conventional high-grain-yield corn varieties according to the density which is increased by 5-10% compared with the recommended density of pure grains; applying a base
fertilizer and a
silicon-
calcium-
magnesium compound
fertilizer at the stem position before the jointing stage, and applying a
nitrogen fertilizer and a
silicon-
calcium fertilizer in the large
bell mouth stage; green-keeping and grain-increasing fertilizer is applied 10-15 days after
spinning, wherein the green-keeping and grain-increasing fertilizer comprises
potash fertilizer,
urea and
phosphate fertilizer; from the final stage of
wax ripening to the initial stage of complete
ripening, when milk lines of the grains disappear or black
layers are formed, the grains are harvested, and the stem and leaf structures of plants which are not completely dried up are kept to be complete; topdressing
nitrogen fertilizer after harvesting, spraying
growth hormone to induce differentiation of stem base regeneration buds, and harvesting the stem bases after the stem base regeneration buds grow and turn green; according to the method, the
plant stem base regeneration buds are induced to differentiate, turn green and grow again, so that
secondary growth and utilization of the corn straws are realized.