Fan blade of large-flow and low-speed fan

A fan blade of a large-flow and low-speed fan comprises a hub sleeve, a fan blade, a fixing rod and a fixing bolt; the fan blade is rigidly connected with the fixing rod through a front end panel, a rear end panel and a plurality of fixing screws; the fan blade connects the fixing rod to the hub sleeve by using a U-shaped hoop; the fan blade is in a flat and straight shape; each section has same blade geometry and is divided into three areas which are a leading edge flow guide area, a middle part pressure increasing area and a trailing edge rectifying area; the leading edge flow guide area accounts for about 10% chord length and can adapt to opposite airflow directions of incoming flows at different linear speeds; the middle part pressure increasing area accounts for 50% chord length afterthe leading edge flow guide area; through blade geometry shape difference, the middle part pressure increasing area generates enough wind pressure rise and has a relative thickness of not less than 15% so that the fixing rod