Abstract: In order to solve the problem that the output power and wavelength of semiconductor laser light source was easily influenced by drive current and working temperature in Brillouin optical fiber sensing system, high-precision constant current drive and temperature control circuit were designed. Deep negative feedback integrated circuit was used to control the laser drive current precisely. Integrated temperature control chip MAX1978 was adopted to control the working current of semiconductor coolers and achieve the accurate controlment of laser working temperature. The results show that the design achieves the adjustment of drive current from 0mA~100mA. The maximum relative error of current control is 0.06%, current stability is 0.02% and the maximum error of temperature control is 0.03℃. Under the condition of temperature control, the stability of optical power is 0.5%, and the largest drift is 0.005dBm. The design can achieve the effective control of current and temperature and ensure the stability of output light.