It is the most convenient and relaxing to do immigration in Spain now. Spain has now sent more than 2 million suites to stay, and the ownership of the house is still permanent. I don't need any intermediary or anything. My sister bought more than 2 million houses in Spain, which can accommodate three people. It seems that after five years, if you want to be naturalized, you can enter. If you don't want to enter, just change your residence permit. It is more convenient not to be naturalized, or you will have to apply for a Chinese visa when you come back. Canada and other countries stipulate how many days a year to get a green card. Spain does not have this rule and can travel freely.

Good luck!