Crowned Miss Grand International 2021 in 4 December 2021 at Bangkok, Thailand, she is the first Vietnamese woman to win this beauty pageant.

She was awarded the Certificate of Merit by the Prime Minister of Vietnam Phạm Minh Chính for Prominent Young Face 2021 (Vietnamese: Gương mặt trẻ tiêu biểu 2021).

[5] During the national costume competition, held on November 30, she wore a costume entitled “Blue Angel” by designer Tín Thái,[6] that featured a pair of huge wings with gilded decorations behind, an elaborated headdress, gloves, as well as bulky platform boots with 8-inch heels that reportedly hindered her walk.

"After that, with the best interview questions in English and Thai, she won the title and was crowned by Miss Grand International 2020, Abena Appiah.

[20] In her capacity as Miss Grand International 2021, she travelled to Thailand,[21] Peru,[22] Ecuador,[23] Colombia,[24] Spain,[25] Angola,[26] Romania,[27] United Kingdom,[28] Malaysia,[29] India,[30] Indonesia,[31] and her home country of Vietnam.

[33] However, her left shoelace came loose and gradually slipped down during her walk, which caused her to trip on the 3D butterfly decorations attached to it and fall on the catwalk.

[34][35] The incident received widespread attention throughout the Vietnamese media, to the point that Thùy Tiên gave her own comments on what exactly happened.