Through field experiment, we explore the impact of long-term drip fertigation on growth and distribution of lychee root and changes of soil PH in different layers of soil in lychee garden. The results show that drip fertigation can significantly promote the growth of lychee roots, and increase the contact area of root and soil; if it experiences six years of drip fertigation successively, the dry weight of root, root length and surface area of root in soil in drip fertigation area, will be 2.29 times, 2.17 times and 2.25 times that in non-drip fertigation area, respectively. The lychee root is mainly distributed in 0-40cm layer of soil, but there is conspicuous difference between drip fertigation area and non-drip fertigation area in terms of root distribution in 0-20cm and 20-40cm layer of soil. Drip fertigation is more favorable for the root to go deep inside the soil. Under long-term drip fertigation, the soil acidification in lychee garden is prominent, and in comparison with non-drip fertigation area, there is the greatest decline in soil PH in 10-20cm layer of soil in drip fertigation area, reaching 1.47 units.