The utility model discloses a railway case roof beam spraying maintenance device, relate to railway case roof beam maintenance technical field, need purpose -made walking dolly to prior art, track andwater tank etc. Lead to the structure complicated, on -the -spot installation is inconvenient, and it is with high costs, the technical problem who is unfavorable for the maintenance, utilize the flexible pipe of spring as the connecting pipe, cooperate with the high -speed joint head, can extend and follow bag spraying maintenance who is used for railway case roof beam that crimples of orifice water spray automatically under water pressure, the present invention has the advantages of simple structure, easy preparation, installation, can also crimple automatically, be favorable to accomodating, the transportation, consequently, has good application prospect and value.