As part of China's Eighth Five-Year Plan scientific and technological project, the DF9 diesel locomotive adopts wheel-to-hollow shaft traction motor full suspension drive system, high-flexibility second-series round springs, lightweight body and other technologies.

[4] In the late 1980s, China Railway faced competition from other modes of transport, so they sought to increase train speeds.

[5] On 29 March 1992, DF9 0002, the second locomotive produced, was sent to the Beijing Ring Railway, where extreme wind conditions occurred before the tests.

While the locomotive reached 160 km/h (99 mph) during trials, setting a new rail speed record in China,[6][2] one of its brake pipes failed due to the wind pressure of 600–800 kPa (87–116 psi).

These included a standardised oil and water piping arrangement, replacement of the original aluminum intercooler with a copper one, modified cabs with air-conditioning and ventilation, and other features present on the DF11s.