A stopping device for a conveying system, comprising: a base; a first piston assembly, fitted in the base, the first piston assembly comprising: a tube part, the tube part comprising a shock absorbing cavity, the shock absorbing cavity containing a pressure medium, the pressure medium being a gaseous pressure medium; and a first core part disposed in the tube part, the first core part having a first movement direction relative to the base, and the first core part comprising a stopping part and a rod part capable of reciprocating in the first movement direction in the shock absorbing cavity, the stopping part being located at a free end of the rod part, wherein the first piston assembly, relative to the base, has a second movement direction perpendicular to the first movement direction; and a second piston assembly, which is fitted in the base and coupled to the first piston assembly, wherein the second piston assembly comprises a second cavity and is configured to move in the second movement direction so as to drive the first piston assembly to move in the second movement direction, so that the first core part has a lowered position in which it has moved out of a movement path of the tray of the conveying system by moving downward in the second movement direction, and an elevated position in which it has returned to the movement path of the tray by moving upward in the second movement direction; characterized in that the base is provided with a duct, which is in fluid connection with both the shock absorbing cavity and the second cavity; and the first piston assembly further comprises an adjustment member passing through the duct, the adjustment member being configured to move in the duct, so as to narrow or widen the connection between the duct and the shock absorbing cavity, such that damping of movement of the first core part in the shock absorbing cavity has different magnitudes. a base; a first piston assembly, fitted in the base, the first piston assembly comprising: a tube part, the tube part comprising a shock absorbing cavity, the shock absorbing cavity containing a pressure medium, the pressure medium being a gaseous pressure medium; and a first core part disposed in the tube part, the first core part having a first movement direction relative to the base, and the first core part comprising a stopping part and a rod part capable of reciprocating in the first movement direction in the shock absorbing cavity, the stopping part being located at a free end of the rod part, wherein the first piston assembly, relative to the base, has a second movement direction perpendicular to the first movement direction; and a tube part, the tube part comprising a shock absorbing cavity, the shock absorbing cavity containing a pressure medium, the pressure medium being a gaseous pressure medium; and a first core part disposed in the tube part, the first core part having a first movement direction relative to the base, and the first core part comprising a stopping part and a rod part capable of reciprocating in the first movement direction in the shock absorbing cavity, the stopping part being located at a free end of the rod part, wherein the first piston assembly, relative to the base, has a second movement direction perpendicular to the first movement direction; and a second piston assembly, which is fitted in the base and coupled to the first piston assembly, wherein the second piston assembly comprises a second cavity and is configured to move in the second movement direction so as to drive the first piston assembly to move in the second movement direction, so that the first core part has a lowered position in which it has moved out of a movement path of the tray of the conveying system by moving downward in the second movement direction, and an elevated position in which it has returned to the movement path of the tray by moving upward in the second movement direction; the base is provided with a duct, which is in fluid connection with both the shock absorbing cavity and the second cavity; and the first piston assembly further comprises an adjustment member passing through the duct, the adjustment member being configured to move in the duct, so as to narrow or widen the connection between the duct and the shock absorbing cavity, such that damping of movement of the first core part in the shock absorbing cavity has different magnitudes.