[Objective] Salt stress is the most important environmental factor affecting wheat germination, growth and production. In order to find out the alleviation effect of biological stimulator of Desmodesmus sp. on salt resistance, growth and physiology of wheat seeds and early seedlings under salt stress, and screening the best applcation concentration can provide a theoretical basis for their application to alleviate the impact of wheat salt stress. [Methods] Through the indoor petri dish cuiture method, wheat seeds grown under 100 mmol/L NaCl salinity stress were treated with 25, 50, 100 and 200 mg/L of Desmodesmus sp. extracts (DAE), and germination and growth parameters were measured after 7 days. [Results] The exogenous addition of DAE treatment alleviated the inhibitory effect of salt stress on wheat seed germination and early seedling growth. It increased the germination rate and leaf water content of wheat seeds under salt stress, promoted the accumulation of biomass, enhanced the activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, as well as the contents of proline, total soluble sugars, soluble proteins, and chlorophyll, but lowered lipid peroxidation, reduced the content of malondialdehyde and membrane permeability. Under 100 mmol/L NaCl stress conditions, the concentration of 25 mg/L DAE had the best mitigating effect on wheat seed germination and early seedling growth inhibition under salt stress. [Conclusion] By promoting the early germination of wheat seeds, The Desmodesmus sp. cell extracts can improved the chlorophyll content, antioxidant enzyme activity, and osmotic adjustment ability of wheat seedlings, improving the adaptability of wheat seeds and early seedlings to salt stress, and enhancing the salt tolerance of force wheat.