The private RatingDog survey showed the index climbed from 52.1 in March, beating the 52 median forecast from economists surveyed by Bloomberg.
The reading signalled faster expansion in services activity and suggested firms were absorbing higher input costs rather than passing them on to customers.
The data points to resilience in China’s services sector even as price shocks from the Iran war continue to ripple through the wider economy.
Is China's services boom a sign of resilience or a fragile bubble about to pop from global shocks?
Can China's service sector truly absorb war-driven inflation, or is a consumer price crisis inevitable?
Caught between its Iranian ally and US forces, how will Beijing secure its vital oil supply?