We introduced a method that can improve the measurement precision of the three-level atom gravimeter by changing the sequence of the pulses. A 3×3 matrix is put forward to describe the propagation of atomic beams, the interaction between the three-level atoms and bichromatic laser fields, and to calculate the phase difference of the atom interferometers. We obtained also the relation between g ravity and the phase difference of the atom gravimeter. It is found that the pre cision of the three-level atom gravimeter can be increased simply by change the sequence of the optical pulses.