Embodiments of the present invention provide an optical signal modulation apparatus and system. The optical signal modulation apparatus includes: a laser, where each of at least one first output end and at least one second output end of the laser is connected to an electro-absorption modulator (EAM), the laser is configured to generate at least two optical signals, where at least one of the optical signals is sent to at least one EAM by using the at least one first output end, and at least one of the optical signals is sent to at least one EAM by using the at least one second output end, and each EAM is configured to modulate a received electrical signal onto the received optical signal for outputting. The apparatus has a simple structure and less complex production.