Ventilation design is one of the most important elements of the overall design of highway tunnels. An appropriate ventilation design should consider such factors as the ventilation effect, construction difficulty, construction equipment and operation cost. The authors mainly introduce the difficulties in the ventilation design of Meigulin tunnel. By means of cause analysis, countermeasure selection and modern quality control concept, the authors successfully solve the difficulties in the ventilation design of the extralong tunnel and achieve good ventilation design quality and excellent economic, technological and social benefits.