Top seed Zheng, runner-up at the Australian Open earlier this year, defeated second-seeded Muchova of the Czech Republic 6-4, 4-6, 6-2.
It is world number seven Zheng's third career title, having also won in Zhengzhou last year.
Qinwen Zheng successfully defends Palermo clay-court title for Olympic boost
China's Qinwen Zheng (21) successfully defended her Palermo clay-court title on Sunday with a three-set win over Karolina Muchova (27) in a major confidence boost ahead of the Olympics.