The invention discloses a fruit anti-cracking nutritional agent and a preparation method thereof. The fruit anti-cracking nutritional agent comprises the following raw materials in part by weight: 5 to 15 parts of sodium carboxymethylcellulose, 3 to 7 parts of calcium, 1 to 5 parts of ethylene glycol, 0.01 to 0.9 part of plant growth regulator and 10 to 20 parts of water. The preparation method comprises the following steps of: (1) dissolving the sodium carboxymethylcellulose with the water so as to obtain sodium carboxymethylcellulose aqueous solution; (2) adding the calcium into the sodium carboxymethylcellulose aqueous solution and heating to the temperature of between 40 and 50 DEG C; and (3) adding the ethylene glycol into the solution obtained in the step (2), stirring at the temperature of between 40 and 50 DEG C for 30 to 40 minutes, lowering the temperature to the normal temperature, adding the plant growth regulator and stirring uniformly so as to obtain the fruit anti-cracking nutritional agent. The medicinal agent forms a film after being applied by spraying, is difficultly dissolved in the water for the second time after being dried, has a controllable thickness and can effectively lower fruit cracking rate by about 10 percent.