This application discloses an optical component apparatus, an optical assembly (20), an optical component, and an optical line terminal. The optical component apparatus includes: a board (100), where at least one driver unit (10) is disposed on the board (100), and the driver unit (10) includes: a laser driver (11), and a matching network (12) and a first connecting piece (13) that are connected to an output end of the laser driver (11); at least one optical assembly (20), where the optical assembly (20) includes an electro-absorption modulated laser (21) and a second connecting piece (22) that is connected to the electro-absorption modulated laser (21), and the first connecting piece (13) and the second connecting piece (22) are detachably electrically connected, where the laser driver (11) outputs a modulation signal (B) to the electro-absorption modulated laser (21), and the electro-absorption modulated laser (21) inputs a laser signal based on the modulation signal (B); and an eye pattern determining chip (30), where the eye pattern determining chip (30) adjusts impedance of the matching network (12) based on the laser signal output by the electro-absorption modulated laser (21), until eye pattern performance of the laser signal that is output by the electro-absorption modulated laser (21) meets a preset standard. The optical component apparatus can reduce a size of the optical assembly (20), reduce power consumption of the optical assembly (20), and improve performance of the optical assembly (20).