Simultaneous interpretation refers to the interpreter's continuous interpretation of content to the audience without interrupting the speaker's speech. It's a method of translation where simultaneous interpreters provide real-time translation through dedicated equipment. This method is suitable for large-scale seminars and international conferences, usually performed by two to three translators.

Simultaneous interpretation, as a method of translation, is characterized by its high efficiency. The average interval between translation of original text and translation is three to four seconds and is up to ten seconds at most. Therefore, it is possible to ensure that the speaker makes a continuous speech without affecting or disrupting the speaker's thinking. It is conducive to the audience's understanding of the full text of the speech. Therefore, “simultaneous interpretation” has become a popular method of translation in the world today, and 95% of international conferences in the world use simultaneous interpretation. At the same time, simultaneous interpretation is very academic and professional. It is usually used in formal international conferences. Therefore, the quality of translators is relatively high. In addition, it is also widely used in foreign affairs, meetings and negotiations, business activities, news media, training courses, television broadcasting, and international arbitration.

During the conference, simultaneous interpreters sit in sound-proof rooms (commonly known as "boxes") and use professional equipment to interpret the content they hear from the headphones into the target language and output it through the microphone. Participants who need simultaneous interpretation services can use the receiving device to adjust their desired language channels and obtain translated information from the headset.

Simultaneous interpretation is an extremely difficult-to-speak language conversion activity that is strictly limited by time. It requires the translator to listen to the source language and use existing topic knowledge to quickly complete the source language information in a very short period of time. The prediction, understanding, memorization and conversion of the data, while listening, organizing, correcting and expressing the target language, speak the target language translation.

At various international conferences, simultaneous interpreters need to use “l(fā)ightning thinking” and superb linguistic skills to successfully overcome the interweaving and interference of multiple tasks, so it is easy to cause energy shortage or difficulty in distributing attention to the brain. According to the provisions of the AIIC (International Conference Interpreters Association), a simultaneous interpreter is qualified as long as he translates 80% of the content of the speaker (90% to 100% of “simultaneous interpretation” is almost impossible). Many people usually speak very quickly. When they deliver speeches, they often only take into account the content of their own speeches. They even mix local accents and even dialects. The interpreter has to mobilize all his knowledge and experience to go all out. The audience who can intentionally slow down to take care of the simultaneous interpreters is not too many, which puts extremely high demands on the quality of practitioners.