Sample pressing device for spectrograph

The invention relates to a sample pressing device for a spectrograph, and the device comprises a base which comprises a base body and a first through hole formed in the base body; the pressing and holding assembly comprises a driving piece, a pressing and holding piece and a limiting piece, at least part of the pressing and holding piece is arranged in the first through hole and can move relative to the base in the axial direction of the first through hole, the driving piece and the limiting piece are both connected to the pressing and holding piece, and the limiting piece has a first state and a second state; when the pressure borne by the pressing piece in the axial direction exceeds a preset threshold value range, the limiting piece is switched from the first state to the second state; in the first state, the limiting piece abuts against the driving piece in the axial direction so that the driving piece can drive the pressing and holding piece to move relative to the base body in the axial direction when r