Numerical method has been used to calculate the P-polarized light absorption in plasma with a density cavity. It turns out that the peak absorption may approach to 100%, far above the peak of about 50% for linear density profile. If the parameters for the cavity are chosen properly, the curves of absorption coefficient versus angle of incidence appear double-peak structure. The density cavity plays the role of a resonator, the field reflected from the cavity interferes destructivel y with that reflected from the first reflection surface, giving negligible total reflection, and hence causing nearly total absorption.