According to the structural characteristics of optical fiber composite overhead ground wire(OPGW), a method of OPGW icing load monitoring based on strain analysis is proposed. A theoretical model of OPGW icing loading monitoring is established which based on the relationship between monitoring temperature, strain of optical fiber and icing thickness. The relationship between the stress and temperature of OPGW and the temperature and strain of the optical fiber is analyzed. An icing monitoring system based on Brillouin optical time domain reflectometer is developed and simulation platforms are built. The accuracy and applicability of the theoretical model of icing monitoring are verified by simulation. This method is applied to the actual transmission line, it proves the feasibility and practicability of OPGW icing load monitoring method which bases on strain analysis by comparing the data with other icing monitoring data.