The invention discloses an 
offshore wind power single 
pile foundation 
pile monitoring device. The device comprises a single 
pile and the monitoring device arranged on the single pile, the monitoring device comprises a 
data collecting device, dynamic inclinometers, a 
vibration acceleration instrument, inclinometers, a earth pressure gauge and an 
osmometer, wherein the 
data collecting device is used for collecting 
monitoring data and transmitting the 
monitoring data to an onshore 
server, the dynamic inclinometers are arranged on the tops of the single pile and a draught fan, the 
vibration acceleration instrument is arranged on the inner wall of the pile body on the top of the single pile, the multiple inclinometers are arranged on the inner sides of towers at different elevations or the pile foundation in the prevailing 
wind direction respectively, and the earth pressure gauge and the 
osmometer are installed in the positions, at different elevations from the 
sludge surface, of the outer wall of the single pile in a 
pairing mode in the prevailing 
wind direction. According to the device, through monitoring of fault hidden troubles such as the stress-strain characteristics of the 
steel tube pile foundation, the resistance of pile-surrounding soil, the 
pore water pressure, the 
vibration acceleration of jacket steel, inclining, flexion, 
deformity and fracture of the towers, foundation uneven settlement and 
corrosion of the steel structure, automatic early warning can be conducted when the above hidden troubles happen, so that reliable 
technical support is provided for safety operation.