The four major railway stations in Beijing (Beijing Railway Station, Beijing West Railway Station, Beijing South Railway Station and Beijing North Railway Station) have not banned the delivery service. However, because these four stations are all large transportation hubs with a large flow of people, in order to ensure the order and safety in the stations, the stations may impose some restrictions on selling food delivery services.

Specifically, the following are some factors that may affect the delivery service:

1. Time limit of delivery: In order not to affect the normal operation of the station, the delivery service may only be carried out during certain time periods, such as morning or evening during off-peak hours.

2. restriction of food delivery location: the station may stipulate that the take-away food delivery service can only be carried out at designated entrances and exits or waiting areas to ensure order and safety in the station.

3. food safety requirements: in order to ensure the food safety of passengers, the station may put forward some food safety requirements for food delivery service, such as wearing masks and maintaining hygiene.

In short, the four major railway stations in Beijing have not completely banned the delivery service, but may impose some restrictions on the delivery service to ensure the normal operation of the stations and the safety of passengers. If you need take-away food delivery service, it is recommended to contact the take-away platform or station customer service in advance to understand the specific service restrictions and requirements.