At present, the optical fiber sensor generally conducts single parameter characterization, but for the power transmission line monitoring, multi-parameter sensing is needed, such as to monitor the line temperature, humidity, tower tilt, line breeze vibration, and so on. However, to realize multi-parameter sensing, many different sensors and information demodulation devices are needed, which is so expensive that it makes the optical fiber sensor cannot be used in the power industry. In particular, the performance of the equipment is greatly decided by the performance of key devices such as lasers, electro-optical modulators, photodetectors, and spectral demodulation components. So, in our work, the InP-based tunable DBR lasers with narrow linewidth, InP-based electro-absorption modulators (EAM), and monolithically integrated opto-electronic circuits based on InP integration platform are studied to satisfy the requirement for optical fiber sensing system. The distributed Bragg reflector (DBR) laser obtained is within C band, and hop free, and the wavelength tunable range is larger than 15nm with laser linewidth less than 500kHz. And by changing the diode temperature or driving current, the output light wavelength can correspondingly change. For the EAM, the pulse extinction ratio is greater than 10dB, and the rising time is less than 20ps, and the insertion loss is less than 6dB. These devices can be used in distributed optical fiber sensing systems, fiber Bragg grating sensors and tunable diode laser absorption spectroscopy apparatuses, and so on.