Abstract: This article discusses the design and implementation of a 100 G tunable laser optical module, and briefly introduces the functions of each module in the MCU. The main technologies involve TEC control, wavelength locking, wavelength tuning, and power compensation. By analyzing the traditional positional proportional integral and differential algorithm, improving the proportional integral and differential algorithm, and using the algorithm to achieve wavelength locking, this can prevent the wavelength drift or even the lock due to the overload of the adjustment during the system adjustment process.