The dipole force's steady solution of a ladder-type three-level atom of nearly equispaced energy level driven by a standing wave is derived from the atomic master equation.The variance of dipole force and the population of the energy level with the detunings,the space and the amplitude are shown by numerical calculation.The results show that the dipole force is proportional to the gradient of amplitude of the standing wave and the coherences between the atomic internal states plays a modulating role on the force,which is the most remarkable near the two-photon resonance point.Besides the levels tend to reach a equal-population and the dipole force tend to be zero as the amplitude of the electric field becomes bigger.