To solve the ventilation difficulty caused by the change of construction organization mode in the late construction period of long tunnel with parallel adit and main tunnel, the problems exist in construction ventilation of tunnel with parallel adit under special construction modes are studied and the corresponding solutions are put forward. In the late construction stage of Xiangluping tunnel entrance section, many working faces are constructed simultaneously, and the ventilation effect of conventional tunnel construction cannot be achieved due to the existence of pollution sources in the main tunnel and the parallel adit. The original ventilation technology solutions are studied, a detailed ventilation calculation is conducted, and the method that increasing the jet air volume to dilute the exhaust gas is adopted to improve the traditional gallery ventilation technology. The method has been successfully applied in late construction stage of entrance section of Xiangluping tunnel, and good ventilation effect has been achieved.