Abstract: As an essential tool for subsurface velocity structure inversion, seismic traveltime tomography is widely applied in geophysical exploration, imaging of the Earth’s internal structure, and oil and gas exploration. However, the traditional Absolute-Difference (AD) method faces challenges in practical applications, such as source origin time errors, inaccurate receiver locations, and insensitivity to local velocity perturbations, which limit its high-resolution imaging capability. To overcome these issues, this paper introduces a seismic traveltime tomography method based on the Differential-Difference (DD) adjoint-state method. By calculating the differential traveltimes between different receiver pairs, this method effectively eliminates systematic errors, including source time offsets and receiver location inaccuracies, thereby improving imaging precision. Through numerical experiments, we systematically analyze the impact of static errors (e.g., source and receiver location errors) on the traditional AD method and verify the robustness of the DD method in scenarios involving static correction errors. The results demonstrate that under the influence of static errors, the DD method maintains high gradient stability, overcomes the error sensitivity inherent in the AD method, and successfully recovers the boundaries and amplitudes of subsurface velocity anomalies with superior error resistance. Quantitative analysis shows that the inversion results of the DD method exhibit higher resolution and accuracy compared to the AD method, particularly under complex surface conditions. This study provides a theoretical basis and technical reference for the application of the differential-difference adjoint-state method in seismic traveltime tomography. It demonstrates significant potential in near surface imaging and high-precision engineering exploration, offering broad application prospects, especially in addressing the long-standing challenges of traditional static correction strategies.