Miss Tse joined the Administrative Service of the Hong Kong Government in August 1984. She has served in various bureaux and departments, including the former Security Branch, the former City and New Territories Administration, the former Economic Services Branch, the former Finance Branch, the former New Airport Projects Co-ordination Office and the former Trade and Industry Branch. She was Deputy Secretary for the Treasury (later renamed Deputy Secretary for Financial Services and the Treasury (Treasury)) from July 1999 to April 2006, Director of Administration from April 2006 to October 2007, and Permanent Secretary, Chief Executive's Office from October 2007 to April 2010.

Miss Tse assumed the post of Permanent Secretary for Commerce and Economic Development (Communications and Technology) on 26 April 2010. Her policy responsibilities include telecommunications, information technology, broadcasting, film and creative industry, and innovation technology.