The invention relates to a variable-
pitch system for detecting a 
snow covering rate of fan blades. The variable-
pitch system comprises a detecting sensor, a detecting 
signal emitting and receiving device, a 
data processing device and a control device, wherein the detecting sensor is used for detecting 
snow covering thickness of the fan blades, a 
fan blade temperature, environment 
wind power and awind direction, and comprises a 
snow covering thickness sensor and a temperature sensor, which are mounted on the fan blades, an environment air speed sensor which is mounted on a fan pole; the detecting 
signal emitting and receiving device is used for emitting a detecting 
signal to the detecting sensor and receiving a real-
time data signal acquired by the detecting sensor; the 
data processing device is used for receiving the real-
time data signal, 
processing the real-
time data information to obtain 
fan blade snow covering rate; and the control device is used for performing 
pitch varying and yawing operation of the corresponding mode on the fan variable-pitch 
system and the yawing system according to the 
fan blade snow covering rate. The variable-pitch system can effectively improve fan operation efficiency, improves windy covered snow treatment ability, effectively avoids harm caused by 
icing of the fan, and protects the fan better.