Semiconductor laser is one of the most important components in optical fiber sensing system. The stability of its output power and wavelength determines the measurement accuracy of the whole optical fiber sensing system. In order to meet the measurement requirements of the sensing system, it is necessary to tune its wavelength, and after tuning to the required wavelength, it needs to have a higher stability. In this paper, the wavelength tuning of semiconductor lasers is studied by temperature control and driving current control. In the past, the tuning is mostly blind. Because the change of driving current will lead to the change of temperature, the two will affect each other. The tuning process is complex, time-consuming and difficult to tune to the best state. In this paper, a 2×2 matrix describing the relationship between wavelength λ and power P as output and driving current I and temperature T as input is presented. The values of four elements in the matrix are determined. Using this matrix, the optimum tuning driving current and temperature can be calculated directly according to the requirements of different wavelength and power, which makes the tuning process more efficient and accurate. High stability TECAL-XV-XV-DAH temperature controller, laser driving circuit and temperature control circuit are designed. Laser tuning with tuning range of 3.2 nm, precision of 0.01 nm, drift of less than 0.002 nm and power fluctuation less than 3 μW is realized.