Abstract: Sweet potato is an important food crop in China.Mechanical transplanting is one of the key factors to restrict its development.According to the agronomic requirements of ridge film mulching，a kind of opening cavities and water injection transplanting machine for sweet potato seedlings with simple structure and reliable use was designed.Whole machine structure，working principle and design of key parts were introduced.And field experiment verification was carried out.Results showed that performance index of this sweet potato seedlings transplanting machine had reached design and standard requirements.It could improve work efficiency and reduce production cost.And its popularization and application prospect was vast.