Skipper Faf du Plessis (58), JP Duminy (45 not out), David Miller (23 not out) and Hashim Amla (22) were the major contributors for the Proteas.
Off-spinner Ravichandran Ashwin claimed three wickets for 22 runs in his four overs.
The winner will meet Sri Lanka, who beat defending champions West Indies in the first semi-final, in Sunday's final in Dhaka.
watch India VS South Africa 2nd Semi-final Match Live Score Highlights