The West Indian, known for his lengthy deliberation and distinctive nod of the head before giving a batsman out, will reach the landmark in the second Test at Kolkata which starts on March 16 where he will be alongside Australia's Darrell Hair.
In recognition of his achievement, the International Cricket Council (ICC) will present Bucknor, also a qualified football referee, with its first Golden Bails Award.
This is part of the governing body's umpire recognition programme which also includes the Bronze Bails Award (for 100 ODI appearances) and Silver Bails Award (for 200 ODIs).
The 58-year-old Jamaican's first Test as an umpire was the fourth match of the series between West Indies and India in Kingston, Jamaica in April 1989.
Bucknor has stood in four conscutive World Cup finals and 131 One-dayers.
England's David Shepherd is the next most experienced Test umpire with 86 matches.