After the political changes, Hong Kong is no longer the same. Foreign countries have taken advantage of this situation to tailor-make new visa channels, making whether to leave or stay become a decision that is close to many people's eyes. Coupled with the COVID-19 epidemic, some people have left Hong Kong to avoid the epidemic. In the middle of last year, Hong Kong's net emigration exceeded 75,000, a record high; last month, Hong Kong's net emigration exceeded 65,000, which was also a new high after the implementation of travel restrictions. The media's search for stories of people living in foreign lands and the images of relatives and friends farewelling at the airport have become evidence of the reappearance of the immigration wave in the eyes of many people. They ask in their hearts: If a large number of Hong Kong people leave Hong Kong, will this still be the original city? There are three related phenomena worth clarifying in this question: how large the exodus is, whether they originally belong to the city, and whether the immigration situation will continue.