The invention discloses a bag-type protective device for a bridge support. The bag-type protective device comprises a bag body, fillers, a filling device, an upper connecting device and a lower connecting device, wherein the bag body is connected to the upper part and lower part of a bridge through the upper and lower connecting devices, and the bridge support and cushion stones are enclosed therein; the bag body is provided with the filling device which adopts different vale structures according to different fillers and is used for adding and releasing the fillers. According to the bag-type protective device for the bridge support, the following technical problems can be solved, requirements on performance of the support material can be reduced, and thereby purchase cost of the support is reduced and meanwhile workload for checking and maintaining the support can be reduced, the support is prevented from being replaced due to the problem about durability, subsequent operating cost and maintenance difficulty of the bridge are reduced, and current traffic situation is prevented from being influenced by replacement of the support.