The invention relates to the technical field of hoisting, in particular to a multi-point length self-adaptive bayonet device, which comprises an upper beam, a lower beam, an upper beam and a lower beam, the two balance rods are symmetrically arranged at one end, far away from the upper beam, of the connecting rod mechanism; the floating jaw structures are connected with the connecting rod mechanism and the balance rod respectively, and the floating jaw structures are used for axially clamping at least two round rods and automatically compensating the length tolerance of the round rods. The connecting rod mechanism can ensure that the floating jaw structure is always kept in a parallel state, the jamming phenomenon of the floating jaw structure is avoided, and the movement track of the jaw is changed into a parallel track from an arc-shaped movement track. The round bars are clamped in the axial direction of the round bars through the floating type jaw mechanisms, so that the contact faces of the floating type jaw mechanisms and the two ends of the round bars are always kept in the perpendicular state, hoisting of the multiple round bars is achieved, when at least two round bars are clamped, clamping is more compact, clamping force is increased, manpower is reduced, and the work hoisting efficiency is improved.