The utility model provides a tank wagon filling device. The utility model discloses tank wagon filling device includes: filling casing line, flow distribution cap and layer of resilient material, outer extremely interior outer sleeve pipe, intermediate casing group and the inner sleeve pipes of including is followed to the filling casing line, and outer sleeve pipe can reciprocate, and intermediate casing organizes the sleeve pipe of establishing including a plurality of mutual covers that reciprocate, inner sleeve pipes's central point puts and is provided with the stay cord, and the end of stay cord is provided with flow distribution cap, and flow distribution cap includes bottom and the lateral wall that sets up around the bottom, is provided with layer of resilient material between bottom and the lateral wall, is provided with a plurality of minutes discharge orifices on the lateral wall, and divides discharge orifice downwardly extending top to layer of resilient material, be formed with the annular groove of undercut on flow distribution cap's the bottom, the annular groove has formed toroidal cavity with layer of resilient material, and the projection of intermediate casing group on flow distribution cap's bottom is located toroidal cavity. The utility model discloses well flow distribution cap possesses certain collection function, solves resource pollution and extravagant problem effectively.