Selenium is an essential trace element for the human body, and humans can supplement selenium from plants. Selenium can promote the germination and growth of plant seeds, showing a typical biphasic effect of' low promotion and high inhibition'. Selenium plays a role in the whole growth cycle of plants by participating in regulating hormone levels and activating the enzyme activity system. In this paper, the effects of selenium on plant seed germination, growth and development, abiotic stress resistance and fruit quality were reviewed, and the effects of selenium on plant growth and metabolism and related physiological and biochemical indexes were analyzed. Future research needs to deeply analyze the interaction mechanism between selenium and other nutrient elements, and develop precision agriculture application technology to optimize the application strategy of selenium fertilizer, taking into account the improvement of crop yield and nutritional quality.