A data acquisition device for a vehicle includes a first body and a second body. A first body includes a first casing, an antenna member, and two cushion pads. A terminal of the first casing forms a recession and two lateral walls of the recession have two pivot members. The antenna member is disposed in the first casing. The two cushion pads are respectively located on the two lateral walls of the recession and circumferentially disposed around the two pivot members. Each of the cushion pads has a core hole and the pivot members are respectively passing through the core holes. The second body includes a second casing and a process device. A terminal of the second casing has a plug part, and the second casing respectively have two pivot holes pivoted on the two pivot members. The processing device is disposed in the second casing.