The Interaction between molecular ion H_2D~+ and ultra-thin solid film is reported for the first time.The importance of H_2D~+ in the areas such as astrophysics is stated and the study on H_2D~+ of recent years is outlined.The formation mechanism for the H_2D~+ under laboratory conditions is also analysed.The structural pattern of H_2D~+ and the mean internuclear separation are determined using Coulomb explosion technique.Once again,the existence of wake effects in the interaction of molecular ions with sol...