The inductively coupled plasma emission spectroscopy （ICP-OES） method was used to determine the selenium-enriched amount and selenium conversion rate， and the two strains of Lactobacillus rhamnosus Lr-1 and Lr-2 with strong selenium-enriched ability were explored in the process of continuous passage for 250 generations. The selenium-enriched capacity was investigated to determine its selenium-enriched stability. On this basis， the response surface method was used to optimize the ratio of the selenium-enriched L. rhamnosus lyophilized protectant. The results showed that the morphology of the strain did not change significantly during the passage of 250 generations. The average selenium content of Lr-1 was 429.99 μg/g， and the average selenium conversion rate was 28.32%. The average selenium content of Lr-2 was 398.14 μg/g， the average selenium conversion rate was 25.57%， and the selenium-enriched ability was relatively stable. The best cryoprotectants for the selenium-enriched L. rhamnosus was 7% trehalose， 10% skim milk powder， 5% sodium glutamate， and its lyophilization survival rate was 89.86%， which was better than no cryoprotectants. The lyophilization survival rate was increased by 81.85%. This study provided a theoretical basis for the development of selenium-enriched lactic acid bacteria food.