  Recent studies of gamma-ray, cosmic-ray and radio data put stringent
constraints on the fraction of primordial black holes (PBHs) in our universe.
In this article, we propose a new indirect method in using the X-ray luminosity
data of cool-core clusters to constrain the evaporating PBH fraction for the
monochromatic, log-normal and power-law mass distributions. The present results
show that the amount of evaporating PBHs only constitutes a minor component of
dark matter for a large parameter space. The constraints are consistent with
and close to that obtained from other cosmic-ray and multi-wavelength
observations.
