Based on the STM32-microprocessor-manipulated,the polarization degradation in a 50 km long distance distributed fiber vibration sensing system was suppressed by using polarization controller in combination with the genetic algorithm.By exploiting the hardware features of STM32 and PCD-M02 polarization control module,related genetic algorithm parameters were optimized to achieve the genetic-algorithm-based polarization control.Experimental results indicate that the approximately public optimal solution could be found by using the STM32-microprocessor-based genetic algorithm in a short time frame,and ultimately to effectively realize polarization control functionality.Our proposed polarization control scheme could be applied in the long distance fiber sensing system that highly requires the real-time as well as integration features.