A tray module is applicable to a chassis. The chassis includes at least two side plates. Each side plate has a guiding portion. The guiding portion includes a first horizontal section and an ascending section, and the ascending section is connected to the first horizontal section. The tray module includes a carrier body, at least two first connecting rods, and at least two second connecting rods. Each first connecting rod has a movable end and a driven end. The movable end is pivotally connected to the carrier body and slidably disposed in the guiding portions. Each second connecting rod has a pivotal end, a pivotal connection portion, and an operating end. The pivotal connection portion is located between the pivotal end and the operating end. Each pivotal end is pivotally connected to the each side plate. Each driven end is pivotally connected to each pivotal connection portion.