Deep neural networks (DNN) are widely used in image recognition, image classification, and other fields. However, as the model size increases, the DNN hardware accelerators face the challenge of higher area overhead and energy consumption. In recent years, stochastic computing (SC) has been considered a way to realize deep neural networks and reduce hardware consumption. A probabilistic compensation algorithm is proposed to solve the accuracy problem of stochastic calculation, and a fully parallel neural network accelerator based on a deterministic method is designed. The software simulation results show that the accuracy of the probability compensation algorithm on the CIFAR-10 data set is 95.32%, which is 14.98% higher than that of the traditional SC algorithm. The accuracy of the deterministic algorithm on the CIFAR-10 dataset is 95.06%, which is 14.72% higher than that of the traditional SC algorithm. The results of Very Large Scale Integration Circuit (VLSI) hardware tests show that the normalized energy efficiency of the fully parallel neural network accelerator based on the deterministic method is improved by 31% compared with the circuit based on binary computing.