The invention discloses an optical 
signal processing method, a photonic neural network 
chip, and a design method of the 
chip. The optical 
signal processing method comprises the following steps: determining to-be-processed data and a target modulation range of an optical 
signal; modulating the initial input optical signal according to the to-be-processed data and the target modulation range to obtain a target input optical signal; performing parallel 
convolution calculation based on the target input optical signal to obtain a target output optical signal; and performing signal conversion on the target output optical signal to obtain an output 
electric signal, and executing corresponding 
processing operation according to the output 
electric signal. An operation module in the photonic neural network 
chip provided by the embodiment of the invention adopts an optical 
matrix multiplier, an accumulator and a 
nonlinear optical element to realize 
convolution parallel calculation of the same layer, so that the network operation efficiency is greatly improved, and the 
advantage of high operation speed of an optical 
simulation accelerator is fully embodied. And meanwhile, in cooperation with electrical storage and control, a multilayer 
optical neural network is constructed, and mature popularization of the 
optical neural network is promoted.