Disclosed is a neural network operation device, including: an operation array including operation units, wherein each operation unit includes: a source terminal, a drain terminal, a gate electrode, a threshold voltage adjustment layer under the gate electrode, and a channel region extending between a source region and a drain region, the threshold voltage adjustment layer is located on the channel region. The gate electrodes of each column of operation units of the operation array are connected together, and each column is used to adjust a weight value according to a threshold voltage adjusted by the threshold voltage adjustment layer. The threshold voltage adjustment layer is a ferroelectric layer.