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The double-nozzle wind tunnel is the major facility to study compressible turbulent mixing layers, through which many important results of compressible mixing layers were obtained, including the discovery of large-scale turbulent structure, the variance characters of the structures, and so on.The further researches on compressible turbulent structures indicate that the description and analysis of the time-space evolution of turbulent structures needs a large set of instantaneous visualization images and continuous fluctuation signals of structures.The double-nozzle wind tunnel which may provide continuously changed convective Mach numbers from low number to high number, and allow for setting up flow visualization and probe measurement apparatus is essential for obtaining a set of experimental data of compressible shear turbulent structure.At present, there is no existing double-nozzle wind tunnel satisfactory for the above requirements.Based on the analysis of the characteristics of existing wind tunnels, an optimization was conducted on the design of double-nozzle wind tunnel structure to satisfy the requirements of turbulent structure research, and a new wind tunnel was built according to the optimization results.In the paper, the optimized general layout and specific design of the new wind tunnel are described in details, at the same time, the photo of the new tunnel, as well as the instantaneous visualization images and the hot wire measurement results of turbulent structures, are also presented.It is testified by the experimental results that the newly-designed-and-built double-nozzle wind tunnel may produce the large amount high-quality experimental images and data necessary for the research of compressible turbulent structures.