The invention discloses an increasing-pressure and exhausting air method for a long and narrow type air duct. A plurality of booster fan components and an air speed detection device are arranged in the long and narrow type air duct; the concrete positions of the booster fan components are set according to calculation; the air speed detection device is adopted to measure the air speed; the pressure in the long and narrow type air duct is adjusted by adopting the booster fan components, so that the air exhausting speed in the whole long and narrow type air duct is consistent. The pressure of an air exhaust fan can be reduced, the energy loss is reduced, meanwhile, the difficulties in matching and selecting of the air exhaust fan can be greatly reduced, and the cost is saved. The increasing-pressure and exhausting air method for the long and narrow type air duct is simple in construction method, is particularly applicable to a long and narrow type subway station air exhaust pipe system with the service radius exceeding 300m, can be beneficial to remarkably improving the air exhausting effect, has stronger practicability, and can be popularized and applied on a large scale.