The invention provides a walnut high-grafting and head-changing method in south high-temperature high-humidity areas, and particularly relates to the technical field of walnut grafting. The walnut high-grafting and head-changing method includes the following steps that stocks with the diameter of 3 cm to 5 cm are selected; scions are provided; layer contacting is formed between the stocks and the scions, and the stocks and the scions are bound. According to multiple years of research, in the walnut high-grafting and head-changing method, the healing rate of grafting openings is 85.7% or above, and the grafting cost is about 20 yuan/plant averagely; formation of high-yield tree forms is early, and the high yield and the stable yield are easy to achieve; for poor-quality low yield forests of 4 years to 5 years, stocks at grafting portions of high-grafting and head-changing trees are controlled to be 3 cm to 5 cm, high-yield tree forms can be formed for 2 years to 3 years popularly, and the yield of the third year can be 1.5 kg/plant to 2 kg/plant; the stocks at the grafting portions are controlled to be 5 cm or above, the high-yield tree forms can be formed for 4 years to 5 years popularly, and the yield of the fifth year can be 1.5 kg/plant to 2 kg/plant.