The density distributions of water molecules and hydrogen bond in a specific nanocapsule at different temperatures were investigated by molecular dynamics simulation. We also analysed the intra-molecule angle and orientation of water molecules. The result indicates that, due to the confinement of carbon nanocapsule, water molecules are distributed mainly in three capsule-like layers, between which there are almost no water molecules. With temperature rising, the peaks of density distribution broaden to the nanotube wall. The hydrogen bonds are distributed similarly and affect the orientation of water molecules. There are a lot of hydrogen bonds at 1000 K, and the nanocapsule break with some molecules coming out at 3100 K.