Silencing box for single level high speed fan

A silencing box for a single level high speed fan is formed by a box body, a cooling air inlet hole, a cooling air outlet pipe and an axial flow fan; the box body and the insides of door leaves adopt a silencing plate; the outsides of the door leaves adopt a galvanized plate; a sound insulation material fills a gap between the silencing plate and the galvanized plate; the silencing box covers the single level high speed fan and has the silencing function, the cooling air inlet hole in the side surface of the box body and the axial flow fan arranged at the cooling air outlet pipe at the top of the box body form a forcible air cooling system, so the interior of the box body and external air are communicated, and the aim of cooling the fan is achieved; the box body is provided with the door leaves, when the fan has a fault, a serviceman can maintain and debug the fan by opening the door leaf; the box body is formed by assembling multiple unit modules, unit modules of different standards and numbers can be selected according to the size of the fan, and transportation and mounting are facilitated.