The invention relates to an integrated circuit with input/output circuits for multiple segments of output current. The integrated circuit comprises an inner circuit, a system DC power supply and multiple input/output circuits. Each input/output circuit is connected between a pin and the inner circuit and comprises an output buffering unit and a load driving circuit. When an optical load is connected with a second pin in the integrated circuit, besides the original output buffering unit can be selected for supplying the driving current to the optical load through the inner circuit, the load driving circuit can be selected for supplying different driving current to different optical loads. Therefore the input/output circuit of the integrated circuit has a driving function to multiple segments of output current.