A domestic tunable external cavity diode laser based on Littrow configuration is designed and constructed,aiming to advance the localization of high-performance lasers and meet the demand for high-quality light sources in fields such as precision spectroscopy and fiber optic sensing. All optical components of this laser are made in China. A compact mechanical structure is designed based on the parameter characteristics of each component. After the completion of the construction,the laser was debugged and optimized to improve the beam quality. The Littrow tunable external cavity diode laser operates in a single longitudinal mode, with a central wavelength of 1580 nm, a maximum wavelength tuning range of 74.06 nm, a tuning speed of 261.256 nm/s, a coherence length of more than 37.5 m and a linewidth of less than 8MHz （0.064 pm）.