He worked as a teacher in Lelčycy town of Homiel region. While studying in graduate school in Minsk in 1986 - 1989, he was one of the founders of the Society of Young Writers "Tutejšyja" (1986), later - the chairman of the society. In 1988 was one of the founders of the Martyrology of Belarus, and was a member of the organising committee of Belarusian Popular Front. In 1990 he was one of the organisers of Belarusian Catholic community.

In 1989 he graduated from the graduate school of the Institute of Literature of the Belarusian Academy of Sciences. From 1989 to 1998 he worked as a junior researcher at the Museum of History of the Belarusian literature, then as the director of the Literary Museum of Maksim Bahdanovič. Worked as a deputy of Minsk City Council of Deputies in 1992 - 1996.

Since 1997 he heads the Belarusian human rights centre "Viasna". In 2007 he was elected vice-president of the International Federation for Human Rights.

In November 2011 he was sentenced to 4.5 years of imprisonment. The court found him guilty of tax evasion. The reason for the prosecution was the information on bank accounts, which Belarusian law-enforcement bodies received from Lithuania and Poland. Bialiacki was recognised as political prisoner and released under amnesty on 21 June 2014.