The tunable laser sources play a crucial role in silicon-based optical chip screening, laser radar and intelligent sensing system with O-band tunable laser sources being particularly suitable for high-speed data center interconnections. The mechanical tunable laser source based on external-cavity feedback is an effective technical means to break through the limitation of the limited tuning range of the monolithically integrated diode laser source and effectively expand its tuning range. Three O-band tunable laser sources are developed, using the gain chip as the seed source, and feeds the laser beam satisfying the grating equation to the gain region of the gain chip through the blazed grating, and achieves the output results of about 100 nm tuning range with outstanding performance, absolute wavelength accuracy better than ±1.6 pm, wavelength stability better than 0.2 pm/1 h and power stability output better than 0.0020 dB/1 h, and the long-term output consistency is studied. The results show that with the excellent characteristics of the precision resonant cavity module and the wavelength locking module, there is great potential to achieve highly reproducible O-band tunable laser output.