A method for preparing an estolide compound and an estolide compound prepared thereby are disclosed. The method for preparing an estolide compound includes: converting biomass fat into a fatty acid; separating the fatty acid into a C16 saturated fatty acid and a C18 unsaturated fatty acid; preparing a linear internal olefin (LIO); increasing an amount of oleic acid through partial hydrogenation of the C18 unsaturated fatty acid; synthesizing an estolide polymer through cross metathesis of the oleic acid; capping the C16 saturated fatty acid onto the estolide polymer; and reacting the estolide polymer with the linear internal olefin.