Steering light into logic pattes with two-dimensional cascaded multimode waveguide is demonstrated.By employing the imaging properties of 2D multimode interference (MMI) and partial phase modulation method,the design ideas and the implementing methods of the 2(2×2) bits type spatial logic steering are discussed;therefore the structure of logical patte is proposed.Numerical simulation is carried out to verify the design in detail by using the beam propagation method.It is expected to realize logic coders by using the integrated optical methods and exploit their potential applications in the field of optical logic.