A passenger boarding bridge having a movable tunnel and braking system includes a brake plate, a brake pin and a triggering device. The brake plate is fixedly disposed at a first tunnel of the plurality of tunnels, and the brake plate is provided with a plurality of brake slots. The brake pin is movably disposed at a second tunnel of the plurality of tunnels, which is sleeve-connected with the first tunnel and can be combined with the brake slot. The triggering device includes a mechanical blocking portion, a linkage mechanism and a tensile spring. The mechanical blocking portion is fixedly disposed at the second tunnel. When the tensile wire rope or the retracting wire rope is broken, the linkage mechanism is driven to move and drives the brake pin to combine with the brake slot, to brake the first tunnel and the second tunnel.