It's described as "hell" training - physical challenges, like crawling through cold streams and climbing hills while carrying logs, that last up to 18 hours a day.
It's the final stage to determine if one is good enough to become a member of the mainland's top anti-terrorism squad, the Falcon Commando Unit.
For many officers, especially those from rural areas, getting into the squad is a career high. It's the mainland's oldest and toughest special-forces programme, and members are taught how to respond to a range of threats, like aeroplane hijackings, bomb disposal and hostage situations.
About 5,000 officers, drawn from the People's Armed Police, belong to special units tasked with fighting terrorism.
"In various provinces, there are different anti-terrorism armed forces with different names. For example, Beijing's counterterrorism team is called the Snow Leopards while Xinjiang's special armed forces is called the Flying Tigers," said Li Wei, director of the anti-terrorism research centre at the China Institutes of Contemporary International Relations.
The Falcons grew out of the mainland's first special forces unit, an anti-hijacking squad set up when the Special Police Academy opened on the outskirts of Beijing in 1982.
The Falcons' entry requirements are stricter than those for other units, according to Xinhua reports. Candidates must be at least deputy squad leaders in the armed police and have served for at least two years. The minimum height requirement for both sexes is 1.75 metres.
At the basic physical fitness level, men must be able to sprint 100 metres in 15 seconds - 17 seconds for women - complete a 400-metre hurdle run within 1 minute 40 seconds and run 5km in 22 minutes. Those who pass the first round must take three months of military training. About 10 per cent of recruits are eliminated in the first phase, according to Xinhua.
The next stage is a three-year programme of specialised training, where they learn survival skills, sharpshooting and hand-to-hand combat.
Officers also run through scenarios built around possible security threats in urban settings, including storming subway cars, tactical raids on buildings, vehicle chase and evasion, and breaching a hijacked airliner to rescue hostages. About 6 per cent of candidates usually drop out in the final round.
President Xi Jinping singled out the brigade earlier this year when he awarded them a new official name and gave them their own flag.
Xi launched a crackdown on terrorism after several attacks in major cities across the country, which authorities have blamed on extremists and Xinjiang separatists.
Security was stepped up across the nation yesterday - the fifth anniversary of riots in Xinjiang's capital, Urumqi, between Han and members of the Uygur ethnic minority in which nearly 200 are known to have died.
"China has learned a lot of counterterrorism training skills from Western countries and it's a must to build up a comprehensive professional special armed-force system to cope with all possible terrorism threats in every city and province in our country," Li said.