Back when China went into lockdown, they really went into lockdown with a better-safe-than-sorry attitude. Individual villages erected roadblocks, urban areas sealed off housing blocks or in the case of Wuhan the entire city. Those measures reduced the geographic spread of the virus.
Then they drove the virus down locally, using temperature measurements to identify potential infections before more specific tests were available, and then later focusing the entire country's testing capacity on hotspots like Wuhan to identify the last remaining infections.
Then when new outbreaks appeared elsewhere in the country, the response has been for surrounding areas to close their borders and isolate everyone who crossed from the affected region recently. That also applies to international travel, with mandatory centralized quarantine for everyone who enters the country.
Those measures haven't kept China entirely virus-free (the official figures are a bit misleading because they don't count asymptomatic cases) but apparently they still feel safe enough to reopen the economy.
Note that this was the results of local governments not trusting the central government to get the outbreak under control and deciding on their own measures fairly autonomously to keep the virus away. (Including weird scenes like Dali intercepting mask shipments destined for Chongqing or police from Hubei and Jiangxi getting into a brawl over whether to open the border or keep it closed.)
Then they drove the virus down locally, using temperature measurements to identify potential infections before more specific tests were available, and then later focusing the entire country's testing capacity on hotspots like Wuhan to identify the last remaining infections.
Then when new outbreaks appeared elsewhere in the country, the response has been for surrounding areas to close their borders and isolate everyone who crossed from the affected region recently. That also applies to international travel, with mandatory centralized quarantine for everyone who enters the country.
Those measures haven't kept China entirely virus-free (the official figures are a bit misleading because they don't count asymptomatic cases) but apparently they still feel safe enough to reopen the economy.
Note that this was the results of local governments not trusting the central government to get the outbreak under control and deciding on their own measures fairly autonomously to keep the virus away. (Including weird scenes like Dali intercepting mask shipments destined for Chongqing or police from Hubei and Jiangxi getting into a brawl over whether to open the border or keep it closed.)