In order to solve such problem that the electronic sensor

which is used presently to detect the opening and closing state of high voltage disconnector

is susceptible to electromagnetic interference

results in inaccurate measurement data and

in case of installing on the conductive arm with high voltage

has the difficulty in obtaining the electricity

a kind of scheme using optical fiber to measure the angle is proposed in accordance with the characteristics of the blade rotation in case of opening and closing operation of the disconnector. The angle measurement is made by reflecting the rotation angle of the blade on the distance of the line. The genetic algorithm（GA）is adopted to optimize BP neutral network（GA-BP）so to compensate the non-linear problem of the designed optical fiber angle sensor. It is concluded by experimental simulation that the optical fiber angle sensor of the BP neutral network model

which is optimized through genetic algorithm and after compensation

has higher performance and

compared with the traditional BP neural network

its mean square error is increased from 0.084 563 to 0.011 828. The degree of fitting is increased from 90.68% to 97.08%and the linearity is increased from 8.26% to 0.83%. On this basis

an experimental platform isset up with SBE27.5 kV/2000 A disconnector as the research object to perform the feasible experimental test on the accuracy which is detected by the optic fiber angle sensor. The experimental results show that the accuracy of the optical fiber angle sensor after non-linear compensation is increased from 7.585 to 0.269

indicating that the scheme has high accuracy and strong feasibility.