The air-conditioning system of high-speed electric multiple unit (EMU) provides a comfortable environment for the occupants, but also consumes a lot of energy. The bodyside window glass accounts for about 30% of bodyside wall area, which has a great influence on the load of air-conditioning system. In this paper, the thermal insulation performance of bodyside window glass under stationary and motion status of train was studied. At the same time, the influences of glass composition and emissivity on thermal insulation were also studied. The results show that under the stationary state of train, as the emissivity of glass increases from 0.070 to 0.837, the thermal transmittance coefficient of laminated-hollow glass increases by 105% and laminated-hollow vacuum composite glass increases by 209%. While under the high-speed motion status of train, the thermal transmittance coefficient of laminated-hollow glass increases by 120% and the laminated-hollow vacuum composite glass increases by 228%.