The invention discloses a water-soluble fertilizer capable of absorbing cadmium in foliage resistance and control paddy rice. The water-soluble fertilizer comprises the following components in percentages by weight: 17% to 22% of amino acids, 5% to 6% of polyglutamic acids, 19% to 28% of a metal chelate compound, 0.5% to 0.8% of a complexing agent and 5% to 8% of a surface active agent. The invention also discloses a preparation method of the water-soluble fertilizer. The preparation method comprises the following steps: (1) adding amino acids and polyglutamic acids into water, heating and stirring to obtain a mother solution A; (2) in a stirring condition, adding the metal chelate compound and the complexing agent into the mother solution A, and obtaining a mother solution B after complete dissolution; (3) in the stirring condition, adding the surface active agent into the mother solution B, and obtaining the water-soluble fertilizer product after complete dissolution. By using the water-soluble fertilizer, the cadmium content of paddy rice can be reduced, the cadmium content of paddy rice accords with the standard of edible safety, the production increase and quality increase ofpaddy rice are promoted, and secondary pollution to the environment is avoided.