The all-optical current transformer(AFOCT) is made up of the optical fiber as the sensor and the optical signal transmission carrier. Optical signal is used as the transmission carrier， and because the optical fiber is easily affected by temperature and has small deformation， the polarization state of optical signal will change in the process of propagation. In this paper， the affection of temperature on the 1/4 wave plate and the fiber sensing ring is analyzed， and the measurement results are optimized. The phase delay of linearly polarized light will change with the change of temperature in 1/4 wave plate made of polarization-maintaining fiber， and the Verde constant of fiber sensing ring is also affected by the environmental temperature. Based on the analysis of the temperature characteristics of the two devices， a temperature compensation optimization scheme is proposed. Compatible with the original optical circuit devices， optical fiber birefringence temperature sensor is designed for the secondary compensation of temperature errors. The maximum range of transformer changes from 0.417% to 0.335% at 70~40 ℃ to meet the requirements of national standard. The product based on the technical solution has passed the inspection of the third party authority and has been applied in the substation project for a long time. The equipment runs stably and the measurement is accurate， which verifies the feasibility and correctness of the scheme.