  It is assumed that heavy dark matter particles $\phi$ with O(TeV) mass
captured by the Sun may decay to relativistic light milli-charged particles
(MCPs). These MCPs could be measured by the IceCube detector. The massless
hidden photon model was taken for MCPs to interact with nuclei, so that the
numbers and fluxes of expected MCPs and neutrinos may be evaluated at IceCube.
Based on the assumption that no events are observed at IceCube in 6 years, the
corresponding upper limits on MCP fluxes were calculated at 90\% C. L.. These
results indicated that MCPs could be directly detected in the secondaries'
energy range O(100GeV)-O(10TeV) at IceCube, when $\epsilon^2\gtrsim10^{-10}$.
And a new region of 0.6 MeV < $m_{MCP}$ < 10 MeV and $6\times10^{-6}$ <
$\epsilon$ $\lesssim$ $10^{-4}$ is ruled out in the $m_{MCP}$-$\epsilon$ plane
with 6 years of IceCube data.
