Long-term and effective detection of epileptic seizures is a crucial aspect of epilepsy monitoring and treatment. Addressing the resource overhead issue of wearable epilepsy detection devices, this paper proposes a lightweight hardware implementation scheme for epilepsy detection based on a reusable architecture empirical mode decomposition (EMD) and K-Nearest Neighbors (KNN). Firstly, EMD is used to extract epileptic features from electroencephalogram (EEG), optimized through a reusable architecture design and sawtooth transform to reduce hardware resource usage. Subsequently, a KNN classifier with similarity judgment mechanism is designed to improve the recognition efficiency. Implemented on TSMC 65 nm process, the circuit area is 1.91 mm2, operates at 1 V and 20 MHz, with a power consumption of 4.034 mW. Evaluation on the Bonn EEG dataset yielded a classification accuracy of 96 %, sensitivity of 98 %, and a single detection delay of 1.51 ms. The hardware design offers a simple structure, high accuracy, and low resource consumption, making it suitable for wearable epilepsy detection devices.