A prestressed concrete-steel hybrid tower structure was proposed to replace a conventional 2 MW steel tubular wind turbine tower structure. The height and section size of the prestressed concrete-steel hybrid tower were optimized by an updated partial swarm optimization algorithm, where the cost was taken as the optimal objective function, and the constraint conditions including the strength, stability and the stiffness of the prestressed concrete and steel tubular segments, as well as the fatigue, natural frequency, and the maximum top deflection of the hybrid tower structure were considered, but the shape of the tower was kept unchanged. The optimization results show that the total construction cost of the prestressed concrete-steel hybrid wind turbine tower satisfying all of the constraint considerations is about 27 % less than that of the conventional steel tubular wind tower.