Orthogonal Time Frequency Space (OTFS) modulation has been verified in high-mobility scenarios as an effective solution to address the Doppler shift effect. To further improve the data transmission efficiency of the system, this paper delves into different channel coding techniques in the Delay-Doppler (DD) domain under OTFS modulation. This paper evaluates the system performance of various encoding schemes under multiple user mobility rates, including Convolutional codes, Turbo codes, Low-Density Parity-Check (LDPC) codes, and Polar codes. Additionally, this paper investigates the impact of adopting different modulation constellation mapping schemes on the system’s Bit Error Rate (BER) and explores strategies for enhancing system performance in high-speed data transmission scenarios. The simulation results show that the code-based system reduces the BER by about 17–35% compared to the uncoded OTFS system. In this case, the LDPC code system has a 10 dB Signal-to-Noise Ratio (SNR) gain. The simulation results demonstrate that combining coding techniques with OTFS modulation can significantly enhance the performance of communication systems in highly dynamic environments, with LDPC and Turbo codes showing notable advantages in performance improvement. The findings of this paper not only highlight the importance of choosing the right coding scheme and provide valuable references for the design of high-speed mobile communication systems in the DD domain.