A structural health monitoring system using multiple fiber Bragg grating sensors (FBG sensors) was developed. The system was designed to measure a large and fast strain change and to measure acoustic emissions (AE) simultaneously. The strain up to 1% and up to 100 kHz was considered. A multiple fiber ring laser was adopted as a light source, consisted of a multiple erbium-doped fiber amplifier (EDFA), an optical circulator, optical couplers, and FBG sensors. Its lasing wavelengths depended on strains loaded to FBG sensors. A CFRP beam-bending test was conducted to confirm the possibility of simultaneous measurement of both strain and AE signals from a single FBG sensor. In the test, signals from a conventional electric resistive strain gage and a piezoelectric AE sensor were revealed to be equivalent to those from the FBG sensor, respectively. The system will be applied to the development of composite structures in the aerospace field, such as Epsilon Launch Vehicle.