In 2014, Lei won the 4th China Women Masters Tournament in Wuxi on tie-break from Ju Wenjun and was awarded the title of Woman Grandmaster (WGM) by FIDE. In 2015, she won the women's open event of the Moscow Open, ahead of World Junior Girls Champion Aleksandra Goryachkina. Lei competed in the Women's World Chess Championship 2015, where she was knocked out in the second round by top seed Humpy Koneru. In December 2015, Lei tied for 1st–5th with Alexander Zubarev, Olexandr Bortnyk, Jure Skoberne and Maximilian Neef in the 32nd Böblingen International Open scoring 7/9 points.