The invention discloses a cross beam mechanism of a bicycle gripper shifting device, for solving the problem of realizing quick, stable and safe clamping and locking of rented bicycles or private bicycles during bicycle picking. The cross beam mechanism is characterized in that a ladder track provided with big-end-up through slot is arranged along the bicycle longitudinal parking direction; a rack is arranged at the position, corresponding to the ladder track, below the ladder track, and is matched with a running gear on the bicycle gripper shifting device; high-speed slide rails are respectively arranged on two sides of the bicycle longitudinal parking direction; the integral deflection of the ladder track and the rack are collected by means of data sensing. Since the front wheel of the bicycle is positioned rapidly, the requirement for linear movement of the whole bicycle during moving is guaranteed. The cross beam mechanism occupies small space, which guarantees stable and flexible running of the gripper shifting device. Single bicycle parking and batched bicycle combined keeping schemes are provided, and a hardware basis is provided for informationalized picking operation.