A linkage apparatus is provided. The linkage apparatus is disposed between a bottom plate and a carrier plate, and the linkage apparatus includes a drag link and an “L” shape swing link. The drag link is rotatably connected to an end of the “L” shape swing link, and the drag link and the bottom plate are connected to a fixing pin by using a horizontal guide groove; a corner in the middle of the swing link is rotatably connected to the bottom plate, and another end is fastened to the carrier plate; another fixing pin connects the bottom plate and the carrier plate. The swing link is driven by the drag link, so that the carrier plate can be driven to vertically move. Therefore, hot plugging of a peripheral component interconnect (PCI) express card fastened on the carrier plate and plugging of another printed circuit board (PCB) that requires two-dimensional plugging can be implemented without interrupting a power supply.