Abstract: In order to solve problems of low sowing efficiency and high labor intensity when sowing with traditional agricultural tools，and it is not suitable to use large-scale planter under complex terrain conditions，a semi-automatic grain planter was designed based on principle of rotating mop.Rotating device was driven by pedal to drive inner bobbin to rotate，and blade was driven by inner bobbin rotating to dig in rotating state.Functions of digging and covering soil were also combined through connecting rod mechanism to realize semi-automatic sowing.The static，fatigue and modal simulation tests and analysis of fixed ring and connecting rod components were carried out by using ANSYS software，which showed that structural design of planter met requirements of mechanical properties.The planter is easy to operate and could improve labor efficiency and sowing quality.Moreover，the planter has advantages of small volume，light weight and low cost，and is suitable for popularization and use.