The invention discloses weak alkaline balanced nutritional salt for vegetables and cold dishes and a preparation method of the weak alkaline balanced nutritional salt and belongs to the field of seasoning salt. The salt is prepared from 84 parts of sodium chloride, 32 parts of potassium chloride, 7 parts of lactate, 0.15 parts of a vitamin complex, 6 parts of mineral salt, 0.12 part of folic acid, 0.26 part of taurine, 4 parts of se-enriched yeast, 6 parts of an amino acid complex, 0.004 part of potassium iodate and 2 parts of a food buffering agent. The preparation method includes the steps that the sodium chloride, the potassium chloride, the lactate, the vitamin complex, the mineral salt, the se-enriched yeast and the amino acid complex are mixed and ground, sieved with a 30-mesh sieve and dried, the folic acid, the taurine and the potassium iodate are added, and the mixture is packaged. The salt has the seasoning function of ordinary salt and further has the health-care function and the function of promoting balanced nutrition.