"喜庆狂欢活动" can be translated into English as "festive celebration event" or "joyous carnival activity", depending on the context and the specific nuance you want to convey.
"Festive celebration event" emphasizes the festive and celebratory nature of the activity, suitable for occasions like festivals, holidays, or special gatherings.
"Joyous carnival activity" conveys a sense of lively, joyful, and possibly somewhat exuberant celebration, often associated with carnivals or similar events.
Choose the one that best fits the context of your description.