Double-section sampling arm

The invention discloses a double-section sampling arm. The double-section sampling arm comprises a bracket assembly, a linear guide rail assembly, a rotary shaft assembly, an arm assembly and a needle assembly, wherein the linear guide rail assembly and the rotary shaft assembly are fixed on the bracket assembly; the linear guide rail assembly is connected with the rotary shaft assembly; the bracket assembly drives the arm assembly to move up and down by the rotary shaft assembly and the linear guide rail assembly; the arm assembly comprises a long arm which is rotatably connected on the rotary shaft assembly and a short arm which is used for connecting the needle assembly; and the short arm is rotatably connected on the end part of the long arm. The double-section sampling arm disclosed by the invention can sample within a range covered by the whole arm assembly under the condition of saving the space, simplifies the structure, shortens the stroke of the needle assembly and improves sampling efficiency.