In 1922, Yen successfully enrolled in the Western Painting Department of the Tokyo Fine Arts School, through a combination of work and study, and there he became acquainted with fellow Taiwanese students in Japan, including Wang Baiyuan, Zhang Qiu-mei, and Liao Chi-chun.

During his time in France, Yen stayed at the Maison du Japon, which provided accommodation for Japanese students, while he studied at the Académie de la Grande Chaumière and Acadèmie Art Moderne.

In 1931, Yen was selected for the Salon d'Automne in France, with his works La Jeune Fille and Parc de Montsouris.

In June of the same year, Liu Chi-hsiang and Yang San-lang traveled by ship to study in France, and Yen was there to greet them when they arrived at the port of Marseille.

By the October of 1932, because of his liver disease, Yen had spent all his savings, so he ended his student life in France and returned to Japan.

At the time, few people who entered the field of commercial design had a fine art background, thinking that advertisements were too profit-oriented.

Yen also revamped the Ka-Tsi to make a new style of handbag, which was exported to Japan and Mainland China, and which became immensely popular during wartime.

Yen also founded the Taiwan Design Art Association, with a number of others, including Chang Wan-chuan, Chen De-wang, Fan Zhuo-zao, Huang Ching-cheng, Hung Jui-lin, Lan Yun-deng, and Hsieh Kuo-yung.

Yen also participated in the project of repairing Chihkan Tower, which was led by the then Tainan City mayor, Hatori Matao.

The female figures are always adorned in elaborate clothing and accessories, reflecting the beauty and dignity of indigenous culture.

In 1951, Yen was appointed as the technical consultant of the Reconstruction Department of Taiwan Provincial Government, where he was responsible for guiding the development of Taiwanese handicrafts.

To fulfill his post, he once again conducted research on handicrafts all over Taiwan, drafting various revitalization proposals and holding handicrafts workshops in different counties and cities, teaching participants to make artificial flowers made with Chinese Rice Paper Plant (Tetrapanax papyrifer), embroidery, weaving, bamboo work, rattan work, and others.

In 1954, the Joint Commission on Rural Reconstruction appointed Yen as the consultant for the Agricultural Economics Division, for which he was asked to conduct a comprehensive survey on the handicrafts of Taiwan; he also received funding to travel to Japan for research, collecting materials, and reorganizing a project to revive the handicrafts of Taiwan.

In terms of the revitalization of Taiwanese craft and the development of the rural economy, Yen was a key person who made significant contributions.

Besides creating large-scale murals to embellish the environment, Yen Shuei-long also participated in landscape planning, with his most notable work being the boulevard on Taipei City’s Dunhua North and South roads.