The invention relates to a seaweed, fruit and vegetable milk slice and a production method thereof. The production method comprises the following steps: weighing seaweeds, fruits and vegetables in a certain proportion, mixing, adding a proper amount of water, pulping, carrying out flash extraction, and separating to obtain a supernatant; carrying out vacuum concentration on the supernatant to obtain a seaweed, fruit and vegetable water extract; evenly mixing the seaweed, fruit and vegetable water extract with defatted milk powder, dextrin and magnesium stearate; and placing the mixture into a tablet machine for tabletting to obtain the seaweed, fruit and vegetable milk slice which comprises the following components in parts by weight: 30-45% of seaweed, fruit and vegetable water extract, 35-45% of defatted milk powder, 10-15% of xylitol, 5-10% of dextrin and 3-5% of magnesium stearate. The milk slice provided by the invention has the advantages of mixed flavor of seaweed, fruit and vegetable, moderate sweet, rich nutrition, smooth and fine surface and complete piece shape, simple manufacture method, reasonable process and strong program, is convenient in operation and is suitable for industrial scale production.