The utility model relates to a semicircle pipe ha fushi geotome. The utility model aims at providing a simple structure, convenient to use, the lower semicircle pipe ha fushi geotome of cost. The utility model provides a: a semicircle pipe ha fushi geotome which characterized in that: have the top connection, the top connection upper end can be connected with the cavity drilling rod, and the top connection lower extreme is coaxial coupling dual -purpose joint, surflaes pipe, pin and box sub, circle sleeve pipe and sampling drill bit in proper order, be equipped with the axially extending boreof intercommunication cavity drilling rod and surflaes pipe in the top connection, be formed with the step I that the round can support the steel ball on axially extending bore's the inner wall, the circle sleeve pipe is formed by the amalgamation of two blocks of semicircle pipes, the intraductal sampler barrel that is equipped with of circle cover, and the coaxial suit of this yuan of sleeve pipe is outside the sampler barrel, the diameter of steel ball is less than the internal diameter of cavity drilling rod. The utility model is suitable for a silt soil layer's drilling original state sample.