Disclosed are an optical waveguide platform with integrated active transmission device and monitoring photodiode. The optical waveguide platform with hybrid integrated optical transmission device and optical active device includes an optical waveguide region formed by stacking a lower cladding layer, a core layer and an upper cladding layer on a substrate; a trench region formed by etching a portion of the optical waveguide region; and a spot expanding region formed on the core layer in the optical waveguide region, in which the optical transmission device is mounted in the trench region and the optical active device is flip-chip bonded to the spot expanding region. The monitoring photodiode is flip-chip bonded to the spot expanding region of the core layer of the optical waveguide, thereby monitoring output light including an optical coupling loss that occurs during flip-chip bonding.