A further 200,000ha of farmland has been earmarked to supply feed once the project is on stream.
The construction began as Russia looks to secure suppliers of dairy products beyond the EU.
Earlier this year Brussels announced it had extended economic sanctions because of Russia’s involvement in the war in Ukraine.
In a tit-for-tat response the Kremlin prolonged its ban on various food imports from the EU, US, Australia, Norway and Canada, including milk and milk products, until August 2016.
Before the Russian ban the EU exported about 300,000t of cheese, roughly 25% of its production.
Mansel Raymond, chairman of Milk Working Party Copa-Cogeca, the umbrella organisation for European agricultural groups, said the ban and the Chino-Russian dairy venture sent a worrying signal to EU dairy farmers.
“The scale of Chinese investment in dairy production is vast. I wonder now whether we will ever get the Russian milk market back,” Mr Raymond told Farmers Weekly.
“Building a 100,000-cow dairy farm is simply mind-boggling. If the project goes ahead and the 100,000 head represents milking cows, this unit alone could produce 800m litres/year.
“In that case, it would equate to 100,000t of cheese – and that would mean this unit alone could produce about 30% of our previous exports to Russia,” Mr Raymond added.
Watch a video of the largest dairy farm currently in operation – China’s 40,000-cow Modern Dairy Company unit.