The invention discloses a fitness folding bed provided with an arm strength exerciser. The fitness folding bed comprises a bed base support, a bed case, speed changers, spring rods, a motor, a sliding component, an operating component, and a saddle component; the operating component is used for driving two threaded rods of different thread directions via chain wheels; the operating component is driven under the guiding effect of the sliding component to enter into or exit the bed case; a connecting rod arranged between the operating component and the sliding component is used for limiting excessive moving of the operating component out of the bed case; an unlocking plate is used for relieving and limiting forward and backward swing of the operating component; a limiting plate is used for limiting and relieving rotating of operating arms; the saddle component is used for users to sitting; a backup plate is used for users to lean against; and the saddle component and the backup plate can be folded when the saddle component and the backup plate are not needed. The fitness folding bed possesses following advantages: all the mechanisms are hidden in the bed case, no extra space is occupied, the bed case can be vertically placed when the fitness folding bed is not used so as to enlarge indoor space, so that it is possible to enlarging indoor space in parties.