Soliton microcombs offer unprecedented laser sources for high-precision ranging due to their merits of high repetition rate, excellent coherence, and compact size. However, high repetition rate limits the nonambiguity range (NAR) of ranging. Previous dual-comb–based methods can extend the NAR, but asynchronous measurement error (AME) is commonly introduced, which greatly limits the ranging accuracy. Here, we propose a cross dual-microcomb absolute ranging scheme based on dispersion-interferometry method. The AME introduced during dynamic measurement is completely eliminated by one-shot spectral sampling, while the NAR is extended from 3 millimeters to 339 meters by Vernier effect when the repetition-rate jitter is 2 hertz. In addition, the excellent system performance has been verified at different distances and the Allan deviation down to 5.63 nanometers after averaging 56 seconds. Our scheme boasts the potential of straightforward chip architecture and minimal detector requirements and provides an advanced method for future high-precision long-distance ranging and miniaturized lidar systems.