Construction of the phase 1 of line 4 started on 5 January 2017.[1] Test run started on 1 September 2021.[2] On 26 December, line 4 started its initial operation.[3]
A southern extension, currently been de facto branch of line 4, is started its construction works on 31 October 2020.[4] Test run of southern extension started on 2 December 2023.[5] It's opened on 1 May 2024, except Ziyunhu which its TOD programmes are not yet completed.[6]
^安徽发布 (2021-08-31). "合肥地铁4号线明天试运行!站点全公开!". www.thepaper.cn. 澎湃新闻. Archived from the original on 2022-07-09. Retrieved 2021-11-23.
^ ab"4号线正式开通运营,合肥轨道交通迈入"5.0"时代". baijiahao.baidu.com (in Chinese (China)). 安徽网. 2021-12-26. Archived from the original on 2022-07-10. Retrieved 2022-01-01.