The computational costs of traditional deep neural network-based person search algorithms are very high， so that these algorithms are difficult to deploy on devices with limited hardware resources and budgets because of high cost and low speed. Aiming at the above problems， a person detection and person re-identification algorithm based on the high-performance inference chip Sophon SC5+ was proposed to optimize the efficiency of deep learning from the algorithm end to the hardware end in a top-down approach. Firstly， by using the lightweight Ghost module to replace the backbone network of YOLOv5s， the parameters and computational cost of the model were greatly reduced. Secondly， Convolutional Block Attention Module （CBAM） attention mechanism was integrated to enhance the feature learning capability and improve the detection precision of the algorithm. Thirdly， the central loss constraint and Non-local attention mechanism were added to the person re-identification module， and the central constrained triple loss and the additional interval cross-entropy loss were combined to optimize the model and improve the performance of the person re-identification algorithm. Finally， based on Sophon SC+， person detection model and person re-identification model were quantized and the final inference model was generated. Experimental results on Market-1501 and DukeMTMC-ReID datasets show that， the mean Average Precisions （mAPs） of the person detection and person re-identification algorithms were improved by at least 43.8 and 25.7 percentage points compared with YOLOv4-tiny， Attribute-Complementary Re-ID Net （ACRN）， Singular Vector Decomposition Net （SVDNet） and other mainstream algorithms. After the implementation of int8 quantization based on Sophon SC5+ chip， although the proposed algorithm has the mAP decreased by 1.7 percentage points， it has the model size reduced by 74.4%. It can be seen that the proposed algorithm can be used in large-scale， city-level person search systems.