In this study, a newly built integrated navigation system using a two-dimensional laser Doppler velocimeter (2D LDV) combined with strapdown inertial navigation system (SINS) to enhance the measurement accuracy of a vehicle being driven is proposed. The basic principle of the 2D LDV is described, and the dead reckoning process is discussed in detail with respect to the newly built system comprising 2D LDV and SINS. The theoretical and experimental results show that the proposed navigation system effectively alleviates the error accumulation effect of the pure SINS. Moreover, compared with the integrated navigation system composed of one-dimensional laser Doppler velocimeter, the 2D LDV improves the accuracy of the carrier velocity measurement, thereby demonstrating the improved navigation accuracy of the proposed navigation system. The dead reckoning position errors of the proposed navigation system in the two experiments are observed to be only 5.9 m and 5.2 m over 2.2 h.