The experiment aimed to study the string roller′ s surface temperature distribution under steady state of the press inking system. Pro/E was used to model the three-dimensional of existing roller structure. FLUENT was used to simulate the string roller′ s internal fluid situation under the steady conditions. Thus, the ink roller′ s surface temperature contour was obtained. The results showed that the existing structure′ s surface temperature was concentrated around 23.6 ℃, the temperature difference was 1.1 ℃. The optimized roller surface temperature was mainly concentrated around 22.87 ℃ after optimization and improvement of the existing roller according to the analysis. The new structure can save an electricity of 12 776 kW·h per year for a printer. Therefore, the new string roller structure can better meet the need of enterprises nowadays to pursue green environmental protection than the existing cooling structure of inner sleeve roller.