Do I need a transit sign when I transfer in Holland?

No, if you transfer, you can stay at the airport without a visa 12-24 hours.

China Southern Airlines and KLM have started direct flights to Amsterdam from Guangzhou, Shanghai, Beijing and Chengdu. If the flight comes from China or a non-Schengen country, China passengers will need to pass immigration check. If the flight comes from Schengen countries (for example, connecting from Frankfurt or Paris), China passengers will not need to go through the entry formalities like citizens of other EU member countries (because they have already gone through the entry formalities in transit countries). It should be noted that different Schengen countries have different requirements for transit stay time. Generally 12-24 hours, you don't need a transit visa until you leave the airport. However, if you want to transit through two cities in Schengen countries (such as Beijing-Amsterdam-Paris-Cairo) continuously, you will be regarded as entering Schengen countries, and you must apply for a transit visa in advance.

Check the validity of passports and visas before departure to avoid unnecessary troubles when entering the country. When going through the entry formalities, it is best to carry with you the documents related to the itinerary, such as the invitation letter, the itinerary for going to Holland, and the contact information of the inviter. When leaving the Netherlands, as long as the visa has not expired, customs officers can leave the country smoothly after stamping the departure stamp on their passports. It should be reminded that due to the increasingly serious illegal immigration and public security problems in the Netherlands, the direct flights from China to Amsterdam are always checked by the airport police. Please note that it is best to express the city you are going to and the purpose of your trip in English. If the foreign language is not good, it is best to have an accompanying interpreter or ask other passengers on the same plane for help.