The Khmer language and culture were heavily influenced by India (Hinduism and Sanskrit) from the 1st to 6th centuries AD, rather than directly by the Qin Chinese state.
The General stepped down from the platform, his boots squelching in the mud. He walked until he was mere paces from the man. Meng Yi spoke in the dialect of Xianyang, the capital. "You build in stone? The Emperor builds in earth and wood. Stone is for the dead. Why do you build for the dead in the land of the living?"
The Qin Empire strictly utilized Old Chinese; Khmer belongs to the unrelated Austroasiatic language family. the qin empire speak khmer
Some theorists argue that the "Old Chinese" spoken during the Qin period shared phonological traits with early Austroasiatic languages, leading to a "transitional" period of speech that modern ears might find surprisingly familiar to Khmer. Middle Khmer and French Influence
To support his military campaigns in the rugged southern terrain, Qin Shi Huang ordered the construction of the in 214 BCE. Connecting the Xiang River (a tributary of the Yangtze) with the Li River (which flows into the Pearl River basin), this magnificent feat of engineering allowed the Qin military to transport supplies directly from the Chinese heartland into the deep south. The Khmer language and culture were heavily influenced
The precursors to the Khmer Empire (like Funan) emerged around the 1st Century AD—centuries after the fall of the Qin Dynasty.
Qin unified regional writing styles into one system. This allowed for communication across different spoken dialects, but it was not Khmer. Meng Yi spoke in the dialect of Xianyang, the capital
Some fringe historical theories attempt to trace the origins of all Southeast Asian civilizations directly to refugees fleeing the harsh rule of the Qin Dynasty. While migrations certainly happened, the Khmer identity and language were already well-established in their own right in the Mekong delta long before Qin Shi Huang's armies marched south. Summary: The Verdict
It is not accurate to say the "Qin Empire" as a unified entity spoke Khmer. Instead, it is more plausible that southern populations conquered by the Qin spoke languages that were part of the linguistic continuum that included ancestral Khmer. Misconceptions and Historical Reality