Abstract: To address the challenges of limited device availability, high maintenance costs, and rigid experimental models inherent in traditional FPGA-based hardware experiment teaching, this paper proposes the construction of an online practical teaching platform based on a high-density FPGA server cluster. This platform achieves high-density deployment of 28 development boards per single rack-mounted server by integrating the data acquisition module within the FPGA chips. This creates a cloud-based experimental environment supporting concurrent access for multiple users. Building upon this platform, this paper adopts a top-down methodology to redesign lab assignments for the Computer Organization course and establishes an automated evaluation system based on black-box testing. Application in experimental teaching demonstrated that the platform can support 239 students simultaneously conducting the full series of Computer Organization experiments, enabling a hardware reuse ratio of 4:1. This solution forms a trinity of novel teaching modes: "virtualization of hardware resources, cloudification of experimental operations, and real-time feedback of evaluation." It breaks the rigid constraints of physical time and space inherent in traditional hardware labs, enabling ubiquitous, self-directed practice for FPGA experiments.