Guided prefabricated ventilation channel

The utility model relates to a guide type prefabricated ventilating duct, which can well prevent odor tainting or polluted air generated among residents of top and bottom floors. The guide type prefabricated ventilating duct is composed of a main air duct and an auxiliary air duct; the internal part of the auxiliary air duct is provided with a guide plate; the guide plate extends to the inclined upper part of main air duct and enters the internal part of the main air duct, and an acute angle is formed on a horizontal surface. An inlet on the auxiliary air duct is elliptical, and the range of the included angle between the guide plate and horizontal surface is between 25 DEG to 70 DEG. The utility model which is suitable for all kinds of civil buildings has the advantages of simple structure and easy realization.