Autophagy is an evolutionarily conserved degradation pathway of lysosomes (in mammals) and vacuoles (in yeasts and plants) from lower yeasts to higher mammals. It wraps unwanted organelles and damaged proteins in a double-membrane structure to transport them to vacuoles for degradation and recycling. In plants, autophagy functions in adaptation to the environment and maintenance of growth and development. This review systematically describes the autophagy process, biological functions, and regulatory mechanisms occurring during plant growth and development and in response to abiotic stresses. It provides a basis for further theoretical research and guidance of agricultural production.