The present disclosure relates to a water tank structure and a vacuum cleaner. The water tank structure includes a tank body and a tank cover assembly. The tank body has an accommodation cavity therein, and an end of the tank body is formed with an opening in communication with the accommodation cavity. The tank cover assembly includes a cover body and at least one flow divider, and the cover body is disposed at an end of the tank body proximate to the opening. The flow divider is in communication with the cover body and the accommodation cavity. The flow divider is configured to divide a fluid stream flowing therethrough into a plurality of fluid streams formed into pairs having paired kinetic energies carried thereby and paired opposing flow directions, such that the kinetic energies of the pairs of fluid streams cancel out.