In this study, line defects and point defects are introduced in a completely two-dimensional square lattice silicon. Using waveguide coupling and linear interference, a three-input all-optical AND gate based on the two-dimensional photonic crystal is proposed herein. The proposed AND gate is simulated using the plane-wave-expansion method and finite-difference time-domain method. Results show that the proposed AND gate has a contrast ratio of not less than 3.5 dB when the input-light wavelength is between 1544 nm and 1555 nm, and the response time reaches the subpicosecond level. The acceptable horizontal offset of the point defect offset dielectric column is between 0.06 μm and 0.19 μm. The proposed solution exhibits a simple structure, a wide operating-wavelength range, a fast response time, and it can realize the AND gate in the case of three inputs. The proposed AND gate has potential applications in the field of an all-optical signal processing system and an integrated optical path.