[2][3] Lee Sheng-mu's elite career began in the 2009 badminton season when he reached the semifinals of the 2009 Korea Open Super Series in the men's doubles with Fang Chieh-min.

[5][6] He and Fang reached the quarterfinals of the 2012 London Olympics losing to Mathias Boe and Carsten Mogensen of Denmark.

[7] After the 2012 Olympics, Lee stopped playing with Fang Chieh-min, partnering with Tsai Chia-hsin instead.

Together they represented Chinese Taipei in the 2016 Rio Olympics, where they failed to progress out of the group stage.

Their top result came in 2010 when they reached the semifinals of the 2010 Paris World Championships and won the bronze medal.