On the morning of September 28, 2021, the section between Yuanheng Avenue Station and Tongluozhai Road Station on the Hefei Rail Transit Line 4 Extension completed the final continuous beam concrete pouring, achieving a double-line breakthrough for this section. This is also the first elevated section to achieve a double-line breakthrough in Hefei Rail Transit's Phase III construction.

It is reported that after departing from Yuanheng Avenue Station, the Yuan-Tong section runs along the green belt in the median of International Avenue and passes through Huanancheng, forming a beautiful central axis. Construction of the first pile for this section began on February 26, 2021, and superstructure construction began on June 20. After 216 days, the double-line breakthrough of the section was successfully achieved.

As of now, the remaining lines of the Phase III project are all advancing vigorously. The southern extension of Line 3, Phase I of Line 7, and Phase I of Line 8 have entered the shield tunneling stage. Among them, the right-line shield for the section from Hetang Road Station to Jinning Road Station on Phase I of Line 8 was launched on August 9, 295 days ahead of the original plan; the right-line shield for the section from Yaogang Road Station to Heping Road Station on the eastern extension of Line 2 was launched 45 days ahead of schedule; and the left-line shield for the section from Yunxiao Road Station to Xiaopaihe Road Station on the southern extension of Line 3 was launched 74 days ahead of schedule. As of now, among the 73 stations in the Phase III project, 13 have completed their main structures; among the 141 shield tunneling sections, 12 are currently being excavated, and 3 single-line shield tunneling sections have been completed.