短答：不能在“普通新建聊天”里直接指定某几段“历史对话”作为上下文自动载入。
但有几种官方支持的替代方案，能实现“把既往内容带进来”的效果：
- 用「Projects（项目）」
- 把相关对话与资料整理到同一个 Project；在该 Project 里开启项目记忆（project-only memory）后，同一项目内的新聊天会自动参考该项目里的其它对话与文件，而不会引用项目外的个人记忆。适合把多条历史对话当作“上下文池”。
- 用「Memory（记忆）」跨会话携带要点
- 让 ChatGPT“记住”关键信息（如偏好、目标、约定格式）；以后任何新聊都可被动引用这些记忆（也可随时关闭/清除）。注意：这是提炼后的要点记忆，不等于把整段历史对话逐字注入当前上下文。
- 直接“导入/附加”历史内容
- 将导出的 conversations.json（或你整理的“上下文包”文档）上传到新聊天；模型会把文件当参考资料检索使用（类似把历史对话当成外部知识库）。这不是一键合并历史记录，但实操有效。
- 团队/企业场景
- 使用 ChatGPT Business/Team 的项目与记忆能力，在组织范围内获得更稳定的跨会话上下文体验与治理选项。
给你的可落地做法
- 现在就把“本次对话要用的历史要点”汇总成一份 context.md（或把若干历史聊天导出后裁剪成要点），在新聊天里上传并说明“请优先参考该文件”。
- 如果你会长期复用某一批历史对话：新建一个 Project → 把相关旧对话移动/复制到该项目里（或把要点文档丢进去）→ 打开项目记忆→ 以后在该项目中新开聊天即可自动“带上下文”。
In a brand-new ChatGPT chat, can I designate one or more past conversations to serve as the context for this session? This is actually a hard requirement.
Short answer: You cannot directly pick specific past chats and have them auto-loaded as context in a normal “new chat.”
That said, there are several official workarounds that effectively “bring prior content in”:
- Projects
- Put the relevant chats and files into the same Project. With project-only memory enabled, new chats inside that Project automatically reference other chats and files within that Project, but not your global personal memory. This is the closest to treating multiple past threads as a shared “context pool.”
- Memory (personal memory)
- Ask ChatGPT to remember distilled key facts (preferences, goals, formatting rules). Any future new chat can draw on that memory. Note this stores summaries/keys, not full transcripts, so it’s not the same as injecting entire past chats.
- Attach/Import the history
- Export prior conversations (or compile a “context pack” document) and upload it into the new chat. The model will treat it like supporting material it can retrieve from—functionally similar to turning past chats into an external knowledge source.
- Team/Business plans
- In org settings, the Projects + Memory setup provides more robust, governed cross-session context for teams.
Practical steps you can use now
- Summarize the essentials from the past threads into a
context.md(or trim exported chats into a concise “context pack”) and upload it in the new chat with a note like “Please prioritize this file as context.” - If you’ll reuse the same set repeatedly: Create a Project → move/copy the relevant old chats (or their distilled docs) into the Project → enable project memory → start new chats inside that Project to inherit that context automatically.