The invention relates to the technical field of medical treatment, and in particular relates to a bed. The bed comprises a linkage control mechanism, a front-section bed board and a middle-section bed board, wherein the front end of the middle-section bed board is rotatably connected to the rear end of the front-section bed board; in a first structure state, the front-section bed board and the middle-section bed board are in level horizontally, and are positioned on a first height position; in a second structure state, the middle-section bed board is positioned on a second height position, the front-section bed board rotates to an upward oblique position, and the second height is smaller than the first height; the linkage control mechanism controls the front-section bed board and the middle-section bed board to be converted between the first structure state and the second structure state in a linkage manner. Therefore, when a user converts between a lying posture and a sitting posture, the stationary center of gravity is kept through the pushing up of the upper body on the front-section bed board and the sinking of the hip on the middle-section bed board, and the comfort, safety and operation convenience in the conversion between the laying posture and the sitting position are improved through the operation that the linkage control mechanism controls the synchronous conversion.