Trinlay Namgyal alias Kadrung Dekhar was born to Dekhar Tsewang Rabten (Silon Lhukhangpa) and Thupten Wangmo, daughter of Dobdrag Teling in Lhasa in 1930. He started his basic education from Lhasa Ngakrong Shar School in 1940. In 1944, he studied finance in Tsikhang Phuntsok Khotpe in Lhasa.
In 1947, he was recruited in Finance Department of the Gaden Podrang Administration. After that he was employed in collection and distribution Office (འདུ་འགོད་ལས་ཁུངས) and simultaneously he was assigned as the recruitment officer for Drongdrak Makar (གྲོང་དྲག་དམག་སྒར།) in five districts including Phenpo and Taktser in Central Tibet.
In 1948, he worked as (བཀའ་ཤག་ཤོད་པ།) and in 1949, he was assigned as the junior military officer in Eastern Tibet under the supervision of Ngapo Ngawang Jigme. In 1951, he returned to Lhasa and served in Kashag (མགྲོན་གཉེར།) for six years.
In 1957, he was promoted as the Cabinet Secretary and served for around a year. In 1959, after the Chinese occupation, he was sentenced to 20 years in prison and his property was confiscated, which led to a severe problems in his family. His wife, Namgyal Choezom, daughter of Gher Marlampa (སྒེར་རྨར་ལམ་པའི་སྲས་མོ།) was forced to survive on her own.
In 1979, he was released from the prison and later became a member of Political of Tibet Autonomous Region.
In 4 March 1985, he escaped to India with his wife and children. From 1 April 1986 to 30 April 1987, he was temporarily employed by former Home Minister, Mr. Wangdu Dorjee in his research on collection of Historical Records.
Soon after in 1987, he died in Dharamsala. He was survived by his wife, a son (United States) and a daughter (Tibet). After his death, his wife became nun and returned to Tibet with her daughter.