Provided are a method and an apparatus for optical communication. The method is implemented in a communication node comprising an input optical modulator array and an output optical modulator array. The input optical modulator array comprises N input optical modulators and the output optical modulator array comprises M input optical modulators, wherein M is larger than a number of the output optical modulators that are covered by one input optical modulator and N is larger than a number of the input optical modulators that cover the same output optical modulator. The method comprises the steps of determining at least two local input areas from the input optical modulator array, the input optical modulators in each local input area being used for receiving non-local signal light; and determining at least two local output areas from the output optical modulator array, the output optical modulators in each local output area being used for transmitting the non-local signal light. The at least two local input areas and the at least two output areas are corresponded in a one-to-one manner; the input optical modulators in one local input area can transmits the signal light to the output optical modulators in corresponding local output area.