Abstract: Ludwieg tube tunnel is employed frequently in hypersonic fundamental studies due to its cost-efficient property and also high flow quality. However, supersonic wind tunnels designed based on Ludwieg tube principle are scarce despite the hypersonic Ludwieg tubes are spreading widely all over the world these days, restricting the experimental studies of supersonic flows in a cost-efficient way. This paper reviewed the design of a variant of conventional hypersonic Ludwieg tube, i.e., the so-called tandem nozzle supersonic wind tunnel, taking the reconstruction of Mach 6 hypersonic Ludwieg tube tunnel from Technical University of Braunschweig as example. By inserting an additional Laval nozzle and a settling chamber, tandem nozzle supersonic wind tunnel is capable to produce supersonic flow lower than that of original hypersonic Ludwieg tube. In this paper, we introduced the aerodynamic design principles of tandem nozzle supersonic wind tunnel first; thereafter, the design for each components of tandem nozzle supersonic wind tunnel, such as the first and second Laval nozzles, the settling chamber, were reviewed and elaborated; next, the development and possible applications of tandem nozzle supersonic wind tunnel were given. Tandem nozzle supersonic wind tunnel can extend the operation capability of original hypersonic Ludwieg tube facility to supersonic flow region with a relatively low price, while it inherits the advantages of the hypersonic Ludwieg tube. This behavior makes it suitable for fundamental research of supersonic flow in academic institutions and universities.