He was born in Yamashiro Province and employed by Iemitsu TOKUGAWA when Sanchi was twelve years old and later adopted by the first Santetsu YASUI and inherited the Yasui family and became the second Sanchi YASUI.
山城国の生まれ、12歳で徳川家光に召し出され、後に1世安井算哲の養子となって安井家を継いで2世安井算知となる。