Abstract: Disclosed in the present invention is an unfolded life jacket which comprises a fixed floating body provided with a notch through which a user's head passes; straps comprising interconnecting straps attached to the fixed floating body, the interconnecting straps being tied with intermeshing loop straps to hold the user's body; a movable floating body comprising a front movable floating block and a rear movable floating block, to which the fixed floating body is attached, respectively, a rope being attached to the front movable floating block and the rear movable floating block, the rope being tied with the intermeshing loop straps, an adhesion part limiting the front movable floating block and the rear movable floating block on the intermeshing loop straps. It helps the user to keep in a vertical state in water so as to stabilize the gravity center and keep the head out of the water surface.