The present invention relates to a manufacturing method of an instant porridge block using whole grains and, more specifically, to a manufacturing method of a food block comprising a washing step, a drying step, a threshing step, a steaming step, a mixing step, and a freezing step, wherein the washing step is a washing step of independently or selectively selecting and mixing unpolished rice, whole wheat and whole barley, which are used as materials, putting in a container, and washing 2-3 times to remove foreign substances； the drying step is a drying step of putting the washed materials into a hot wind drier and drying at 55-65°；C for 5-6 hours； the threshing step is a threshing step of threshing the dried materials with a thresher to separate to rice and rice bran； the steaming step is a steaming step of mixing the threshed and separated rice and rice bran at a mixing ratio of 8:2 of based on the weight, precipitating in a container, and steaming at 90-100°；C for 45-55 minutes with a steamer to make porridge； the mixing step is a mixing step of independently or selectively selecting chopped apple, pear, and strawberry and mixing at 20-50% based on the weight of the processed porridge after the steaming, and independently or selectively selecting vitamin and calcium and adding at 5-10% based on the weight of materials measured after the threshing in the threshing step； and the freezing step is a freezing step of putting the porridge into a freezing chamber and freezing at -20 to -30°；C for 12 hours. [Reference numerals] (AA) Material (unpolished rice) stock and storage； (BB) Washing； (CC) Drying； (DD) Threshing and crushing； (EE) Input into pan； (FF) Steaming and mixing； (GG) Mixing； (HH) Freezing； (II) Drying； (JJ) Output from pan； (KK) Storage and product； (LL) Sensory test； (MM) Washing 2-3 times； (NN) Drying with heat at 55-65°；C for 4-6 hours； (OO) Thresh unpolished rice to produce polished rice and rice bran； (PP) Crush grain into 6-8 parts； (QQ)
