To travel by train from London in the United Kingdom to Paris in France, you have to cross the Channel.
The fastest option is by direct Eurostar train from London to Lille or Paris. If you want to save money, think about using a bus.
伦敦 - 巴黎 @ 14.11.2019
1 伦敦 (英国) - 巴黎 (法国)
To travel from London to Paris by train, you have to use the direct Eurostar train. The journey time is about 2:30 h.
Buy your train ticket for Eurostar and find schedules via the given booking links. As earlier you book, as cheaper the ticket prices are.
An other travel option is to use a bus. The journey is much longer, but usually cheaper. Flixbus runs this route several times per day, but as well other bus companies.
The journey by train and including the ferry Dover (United Kingdom) to Calais (France) is for now no nice option anymore. The journey is long and the ferry got really expensive for foot passengers since several years.
Eurail: 如果如果在这条路线上您想使用Eurail而不是火车票, 请您查看这里，关于预订费及其他信息。