Abstract: A bag forming device and a bag machine are provided. The bag forming device comprises at least two bag forming units, wherein each bag forming unit comprises a deflection element and a folding element, and the forming tubes of the folding elements are arranged in a first direction in sequence. The packaging film is moved in a moving route when moving through the deflection element, and film moving positions are provided in the deflection element in the moving route for passing through of the packaging film to make deflection of the packaging film. The present invention reasonably adjusts the moving direction of the packaging films, and the direction of the longitudinal openings of the packaging films after longitudinal folding.