The invention relates to the technical field of test instrument sample showing, in particular to a sample placement showing device of a test instrument. The sample placement showing device comprises a rectangular base. A rectangular box is installed on the upper wall face of the rectangular base. A rectangular through hole is formed in the front wall face of the rectangular box. A pair of partition plates are installed on the inner side wall face of the rectangular box. First strip-shaped grooves are formed in the upper wall faces of the partition plates. First strip-shaped sliding rails are installed inside the first strip-shaped grooves. A plurality of first movable wheels are installed on the first strip-shaped sliding rails. A supporting base is installed on the upper wall faces of the first movable wheels. A first groove is formed in the upper wall face of the supporting base. A first driving supporting frame is installed inside the first groove. The sample placement showing device is novel in structure, convenient to operate, a user is effectively helped to place the test instrument, the user can directly check a detector sample, and the user can know the test instrument more clearly and conveniently.