The invention provides a load self-adaptive variable voltage constant current source circuit, and belongs to the technical field of electronic equipment, the main structure comprises a current settingmodule (1), an amplitude limiting module (2), a power output module (3), a load judgment module (4), a delay compensation module (5), a voltage tracking module (6) and a power-off protection module (8). According to the load self-adaptive variable voltage constant current source circuit, load change can be actively adapted during the working process, the circuit has the advantages of high efficiency, wide load adapting range, high safety, high reliability and the like.