Objective: To synthesize 3'-deoxy-3'-18F-fluorotyhymidine (18F-FLT) using CFN-MPS-200 automatic synthesis module, and evaluate its distribution in Wistar rats. Methods: We used 3-N-Boc-5'-0-dimethoxytrityl-3-Onosyl-thymidine (Boc-FLT)-percursor as raw material to synthesize 18F-FLT without residual solvents. Its radiochemical purity was confirmed with radio-HPLC and thin layer chromatography (TLC). Normal Wistar rats were injected with 18F-FLT and underwent PET scanning. Results: The entire preparation procedure took about 60 min, which resulted in a radio chemical yield of (24±5)% (after attenuation correction, n = 20) and radiochemical purity of over 99%, with 1. 11×109 Bq/ml. specific activity. The 18F-FLT solution was colorless and had a pH value between 7. 0-8. 0. 18F-FLT was mainly concentrated in the kidney, bladder, liver, bone marrow and Liver of normal Wistar rats. Conclusion: Automated synthesis of 18F-FLT using CFN-MPS-200 is a stable method, with high yield, safety without solvent, and acceptable quality.