Distributed denial of service (DDoS) attack, as a traditional network attack method, still poses a great threat to network security. This study proposes a DDoS attack identification method implemented at the hardware level on the basis of the construction mode of a high-performance network security chip system on chip (SoC)+IP to handle network-layer DDoS attacks. According to the design principle for hardware protocol stacks, the logic circuit gate is used to process network packets in a manner of disassembly and analysis. Then, attack determination in the disassembled information is conducted, and the information of the packets identified as attacks is recorded into the attack pool, waiting to be read by the host at any time. Furthermore, an intellectual property (IP) core for DDoS attack identification based on the proposed method is implemented by a hardware logic circuit, and the IP core is controlled by means of advanced high-performance bus (AHB) configuration registers. Comprehensive and functional tests are performed on the system verilog/universal verification methodology (SV/UVM)-based simulation and verification platform. The experiments show that the IP core meets the design requirements and can perform DDoS attack identification and detection in real time to effectively improve the security protection function of the high-performance network security chip.