Photon polarization state in aerial fiber for power grid is susceptible to the rapid external random disturbances, which leads to low coding rate of polarization-coded quantum key distribution (QKD) system or even zero coding rate. To counter the rapid change of polarization state in the link, we design polarization feedback system (FPF), and describe the working principle of the system. The key polarization feedback algorithms in the system are studied, including the selection of evaluation function and search algorithm of polarization convergence, the selection of monitoring conditions of polarization feedback cycle and coding cycle, and the adaptive selection of monitoring threshold. The whole system is measured on actual aerial fibers. The test results show that the system and algorithm can solve the problem of QKD code in intermediate-distance installed aerial fiber.