An optical-electrical converting device includes a first substrate, a planar waveguide, a bearing member, a reflective member, a second substrate, a laser beam emitting member, and a driving chip. The first substrate includes a supporting surface. The planar waveguide is supported on the supporting surface, and includes a laser beam incident surface. The bearing member is supported on the supporting surface, and includes a sloped surface aligned with the laser beam incident surface. The reflective member is positioned on the sloped surface. The second substrate is supported on both the bearing member and the planar waveguide. The second substrate comprising a lower surface and an upper surface. The laser beam emitting member is positioned on the lower surface, and includes a laser beam emitting surface aligned with the reflective member. The driving chip is positioned on the upper surface, and is electrically connected to the laser beam emitting member.