At present, the train does not support the use of wifi, so there is no wifi password. Wi-fi is a technology that can connect personal computers and handheld devices (such as PADs and mobile phones) wirelessly. It is actually a high-frequency radio signal. Wi-Fi is really a brand of wireless network communication technology. Organized by the wi-fi alliance. The purpose is to improve the interoperability between wireless network products based on ieee 802. 1 1 standard. Some people call the local area network using ieee 802. 1 1 series protocols wi-fi. Even equate Wi-Fi with wireless Internet (Wi-Fi is an important part of wlan). A password is required to mark the free wifi connection in the train compartment. Why do you need a free password? -... I know there is the largest train wifi, and the signal is called rail-wifi. There is no password and there is no charge for the connection. However, it seems that you have to download a software to use it.