VHF data exchange system is one of the main communication methods in the e-navigation strategy led by the international maritime organization. Among them, VDE-TER business divides many kinds of business logical channels according to physical channel characteristics. In order to improve the data transmission efficiency under the premise of ensuring the transmission quality of the VDE-TER channel, this paper proposes an improvement of Max-Log-Map based on a priori correction factor based on an in-depth analysis of the Turbo encoding and decoding algorithms under different service logic channels of the VDE-TER algorithm. According to the Turbo coding characteristics of VDE-TER different service logical channels, the algorithm realizes the determination of the optimal correction factor value of the specific logical channel of VDE-TER through simulation and the performance test of large samples of actual physical channels. The results show that the performance of the decoding algorithm with correction factor is improved by 0.6~0.8 dB gain compared with the traditional decoding algorithm, which lays a theoretical and technical foundation for the development of high-performance VDES products.