The error of commercial optical current transducer（OCT）must be less than 0.2%.The magneto-optical probe is a key component for high-accuracy current sensing

and the influences on measuring accuracy are analyzed

which are introduced by the defects of the magneto-optical probe.In the meanwhile

the reasons which affect the stability and sensitivity of the optical current transducer are described by analyzing the assembly technics.The theoretical analysis and digital simulation of the physical defects and assembly process are developed sufficiently

so it is valuable for solving a great deal of problems

such as the design of magneto-optical probe

measurement accuracy

measurement sensitivity

et al.