The invention discloses an acceleration processing unit based on a convolutional neural network, and is used for performing convolution operation on local data. The local data include multiple multimedia data. The acceleration processing unit comprises a first register, a second register, a third register, a fourth register, a fifth register, a multiplier, an adder, a first multipath selector and a second multipath selector. The single acceleration processing unit controls the first multipath selector and the second multipath selector so that the multiplier and the adder are enabled to be repeatedly usable, one acceleration processing unit is enabled to only need one multiplier and one adder to complete convolution operation and use of the multiplier and the adder can be reduced. Processing speed can be enhanced and energy consumption can be reduced by reducing use of the multiplier and the adder in implementing the same convolution operation, and the on-chip area of the single acceleration processing unit is smaller.