A movable tunnel braking system for a passenger boarding bridge, the passenger boarding bridge comprising a plurality of tunnels (22, 23) sleeve-connected sequentially and a tensile wire rope and a retracting wire rope that are connected to the plurality of the tunnels (22, 23), wherein the movable tunnel braking system comprises: a brake plate that is configured to be fixedly disposed at a first tunnel of the plurality of tunnels (22, 23), wherein the brake plate is provided with a plurality of brake slots; a brake pin that is configured to be movably disposed at a second tunnel of the plurality of tunnels (22, 23), which is sleeve-connected with the first tunnel and configured to be combined with the brake slot; and a triggering device, comprising: a mechanical blocking portion (231, 233) that is configured to be fixedly disposed at the second tunnel; a linkage mechanism that is configured to be movably disposed at the second tunnel, and is configured to be connected to one end of the tensile wire rope or the retracting wire rope, wherein the linkage mechanism is configured to abut against the mechanical blocking portion (231, 233) under action of a tension of the tensile wire rope or the retracting wire rope; and a tensile spring (71, 72) that has two ends respectively connected to the linkage mechanism and configured to be connected to the second tunnel, so that 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. a brake plate that is configured to be fixedly disposed at a first tunnel of the plurality of tunnels (22, 23), wherein the brake plate is provided with a plurality of brake slots; a brake pin that is configured to be movably disposed at a second tunnel of the plurality of tunnels (22, 23), which is sleeve-connected with the first tunnel and configured to be combined with the brake slot; and a triggering device, comprising: a mechanical blocking portion (231, 233) that is configured to be fixedly disposed at the second tunnel; a linkage mechanism that is configured to be movably disposed at the second tunnel, and is configured to be connected to one end of the tensile wire rope or the retracting wire rope, wherein the linkage mechanism is configured to abut against the mechanical blocking portion (231, 233) under action of a tension of the tensile wire rope or the retracting wire rope; and a mechanical blocking portion (231, 233) that is configured to be fixedly disposed at the second tunnel; a linkage mechanism that is configured to be movably disposed at the second tunnel, and is configured to be connected to one end of the tensile wire rope or the retracting wire rope, wherein the linkage mechanism is configured to abut against the mechanical blocking portion (231, 233) under action of a tension of the tensile wire rope or the retracting wire rope; and a tensile spring (71, 72) that has two ends respectively connected to the linkage mechanism and configured to be connected to the second tunnel, so that 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.