The invention relates to a composite growth regulator for beet stress-resistant yield and sugar-increased seedling stage and a using method thereof. The composite growth regulator is prepared from plant hormone, Ca2 and various signal substances, is particularly suitable for saline and arid environment conditions, and can induce the expression of beet stress-resistant genes and accelerate coordination and unification between the beet and the environment, the individual and population, the root and the overground part, the external form of the plant and internal physiological function. After the beet is transplanted, the salinization resistance, drought resistance and disease resistance can be effectively enhanced; and the problem that the beet yield and the sugar content resulted from the influence of salinization, drought and disease spreading are reduced year by year is solved. The regulator also has the characteristics of a common strong-seedling agent and also can solve the problems of vain growth, disease susceptibility and weak seedlings of the young seedlings in the beet seeding culture process; the beet root yield under the saline and arid environment conditions reaches 47,267.47kg/hm<2>, the yield is increased by 16 to 18 percent; the sugar content is 16.1 percent, and is increased by 0.9 to 1.2 percent; and the effects of increasing the yield and sugar are obvious.