Hsieh and China's Peng, who are into the Madrid Open semi-finals, will be listed as joint world number ones in the new rankings released on Monday.
"Reaching number one in the world is a great feeling," said Hsieh, 28. "We have been working really hard as a team.
"I was very proud Peng reached number one earlier this year and now I am happy we can share it."
Hsieh and Peng have won 11 WTA titles together and have never lost a final. They are the 10th doubles team to be listed as co-number ones.
"Not only are Hsieh and Peng a great doubles team, but they are an inspiration to the fans throughout the Asia-Pacific region."
Hsieh and Peng, who reached the top doubles ranking in February, will face Spain's Garbine Muguruza and Carla Suarez Navarro in the Madrid semi-finals on Friday.
