Based on multiyear INTEGRAL observations of SS433 in 2003-2011 , a composite IBIS/ISGRI 18-60 keV orbital light curve is constructed around zero precessional phases \psi _ { pr } = 0 at the maximim accretion disk opening angle .
It shows a peculiar shape with significant excess near the orbital phase \phi _ { orb } = 0.25 , which is not seen in the softer 2-10 keV energy band .
The 40-60 keV orbital light curve demonstrates two almost equal humps at phases \sim 0.25 and \sim 0.75 , most likely due to nutation effects of the accretion disk .
The nutational variability of SS433 in 15-50 keV with a period of \simeq 6 ^ { d } .290 is independently found from analysis of Swift/BAT data .
The change of the off-eclipse 18-60 keV X-ray flux with the precessional phase shows a double-wave form with strong primary maximum at \psi _ { pr } = 0 and weak but significant secondary maximum at \psi _ { pr } = 0.6 .
A weak variability of the 18-60 keV flux in the middle of the orbital eclipse correlated with the disk precessional phase is also observed .
The joint analysis of the broadband 18-60 keV orbital and precessional light curves confirms the presence of a hot extended corona in the central parts of the supercritical accretion disk and constrains the binary mass ratio in SS433 in the range 0.5 \gtrsim q \gtrsim 0.3 , suggesting the black hole nature of the compact object .