A caisson block construction method, including: manufacturing a plurality of bottom caisson blocks having a plurality of first unit compartments disposed consecutively in a horizontal direction; manufacturing a plurality of upper caisson blocks having a plurality of second unit compartments; forming a bottom caisson block structure by installing the plurality of bottom caisson blocks side by side in the horizontal direction; installing the plurality of upper caisson blocks above the installed bottom caisson blocks; filling with rubble the second unit compartment of the upper caisson block positioned above the first unit compartment for rubble and exposed upward; inserting a vertical reinforcing bar module after the upper caisson blocks are installed; and forming a vertical concrete column for joining by casting concrete into the upper part of the second unit compartment in which the vertical reinforcing bar module is inserted.