Design of wavelength control of a tunable laser with the wavelength tunable range from 1310 nm to 1319 nm is introduced and its feasibility is verified by experimental tests. The laser chip adopted by this system is distributed feedback (DFB) laser array based on reconstruction-equivalent-chirp (REC) technology and the realization of wavelength tunning is based on the interaction between the upper computer [personal computer, (PC)] and lower computer [micro controller unit, (MCU)]. The results demonstrate that this system applied to dense wavelength division multiplexing (DWDM) in 50 GHz spacing at 1310 nm can keep the wavelength accuracy within the range of 0.01 nm.