A load support apparatus for a cabin of heavy equipment is capable of overcoming the problems that a vibration absorption apparatus is very efficient for absorbing vibrations transferred from an upper frame to a cabin when heavy equipment runs or does work but is less efficient with respect to the left and right direction vibrations. The load support apparatus of a cabin of heavy equipment comprises a vibration prevention member which is engaged with an outer side of the cabin, a support bracket which is installed on an upper side of the upper frame and receives the vibration prevention member therein, and an elastic member which is installed between an outer side of the vibration prevention member and an inner side of the support bracket and absorbs the left and right direction vibrations which are transferred from the upper frame to the cabin.