The invention provides a track vibration damper and a rail transit system and relates to the technical field of track vibration damping. The track vibration damper comprises a vibration direction changing mechanism and a vibration absorber; elastic waves spreading in the up-and-down direction pass through the vibration direction changing mechanism; the vibration direction changing mechanism can change the spreading direction of partial elastic waves to form direction-changed waves; the direction-changed waves are sent out from the side wall of the vibration direction changing mechanism; the vibration absorber is arranged on the side wall; the spreading direction of the other part of elastic waves is not changed so that transmitted waves are formed; transmitted waves are sent out from the bottom of the vibration direction changing mechanism; the rail transit system comprises a track body and the track vibration damper; and the vibration direction changing mechanism of the track vibration damper is connected to the bottom of the track body. The track vibration damper has a better vibration damping effect on the track body.