Nowadays, in order to meet the high-speed date transmission services, a new generation of long-term evolution of mobile communication system (LTE) came inter being. And the uplink used single carrier frequency division multiplexing (SC-FDMA) technology. However, the increase of Doppler frequency shift at high speed produce the channel's fast time-varying fading and destroy the orthogonality between subcarriers, which makes the performance of the system especially the uplink be seriously affected. In this paper, therefore, for the uplink transmission system in high-speed mobile environment, the study was carried out from the uplink Doppler frequency offset estimation technique in the high-speed railway communication system. The uplink channel is modeled and the existing algorithm of traditional frequency offset estimation is studied. The improved frequency offset estimation algorithm is proposed. In the high-speed scenario, the improved method adopted the method of rough estimation and refinement and used the auto regressive model to track the frequency offset estimation between subframes, thus improving the accuracy of estimation, reducing the interference of noise and the complicated calculation degree. The problem of frequency offset estimation of uplink transmission system under high speed scenario is solved to a large extent. The improved algorithm was compared with the performance of the existing algorithm. The results shows that the improved algorithm had a better performance gain.