A computer input device includes a housing, a move tracking module, and a light pervious plate. The move tracking module is disposed in the housing, and emits a sensing light. The light pervious plate is movably disposed between the housing and the move tracking module, and may be moved between a first position and a second position relatively to the move tracking module. In this manner, the sensing light selectively penetrates the light pervious plate and is emits out of the housing, or is directly emits out of the housing, so that the computer input device correspondingly executes a touch mode or a mouse mode.