Synergistically improving the strengthStrength and plasticity of X80 pipeline steelX80 Pipeline Steel is crucial for ensuring the safe transportation of oil and gas. This study proposed a novel approach based on hot rolling technology, using cryogenic treatmentCryogenic Treatment to regulate the microstructureMicrostructure and propertiesProperties of pipeline steelSteel. Its effects were quantitatively analyzed. The results indicated that after 15 h of cryogenic treatmentCryogenic Treatment, the X80 steelSteel achieved a 14.4% increase in post-uniform elongation while simultaneously enhancing its tensile strengthStrength by 8.0%. Further microstructural characterizationCharacterization revealed that the primary mechanisms responsible for the improvement in strengthStrength and plasticity were grain refinement and an increased dislocation densityDensity within the steelSteel. Quantitative analysis indicated no significant change in the phase composition of the pipeline steelSteel before and after cryogenic treatmentCryogenic Treatment. In addition, the grain sizeGrain size was reduced by 13.9% after treatment. Notably, the dislocation densityDensity increased from 2.46 × 1014 to 2.82 × 1014 m−2. This study provides a fundamental basis for the application of cryogenic treatmentCryogenic Treatment in regulating the microstructureMicrostructure and propertiesProperties of pipeline steelsSteel.