The top of the bogie area of high-speed trains is the most dominant position of the interior noise. Using a combination of experimental analysis and simulation prediction, the interior noise mechanism above the bogie area is studied based on the noise mechanism of the “source-path-response”interior.The vibration and sound characteristics, structural optimization of the floor and prediction of the noise in the bogie area are investigated. The conclusions are as follows: there are significant peaks of the interior noise in the frequency range of 500~800 Hz above the bogie area. Among them, the sound transmission path above 500 Hz mainly comes from the air transmission path, and the sound transmission path below 200 Hz mainly comes from the structure. The noise in the car is negatively correlated with the sound insulation of the floor, and positively correlated with the vibration acceleration level of the floor. With the increase of the sound insulation or the decrease of the vibration acceleration level, their impact on the interior noise is gradually decreasing. The sound insulation design of the floor needs to be further studied from the new structure and new materials. The research results can provide reference and basis for noise control in high-speed trains.