Prior to his current role, Diên served as the Deputy Head of the Central Committee's Propaganda Department from May 2020 to April 2021.

He held various positions within the party structure in Thái Bình Province before rising to higher offices at the provincial level.

Under his leadership, the Ministry of Industry and Trade has worked to enhance Vietnam's competitiveness in the global market and attract foreign investment.

Diên has also focused on addressing challenges related to trade barriers, market access, and the development of key industries such as manufacturing, energy, and agriculture.

He has advocated for reforms to improve the business environment and facilitate trade, including efforts to streamline regulations, reduce bureaucracy, and enhance transparency.