Abstract: This paper introduces an aircraft electrical testing system based on PC104, designs the hardware and software structure of the testing system, and explores in depth the testing algorithms for aircraft electrical parameters. The human-machine interface and various testing parameter algorithms were designed using C language. With the help of the PC104 system, the system, composed of analog and control circuits, was used to control and test the aircraft electrical parameters. Testing on an actual aircraft power supply network shows that this testing system has the advantages of being portable, easy to operate, having complete testing functions, and high testing accuracy, making it worthy of widespread application. Keywords: PC/104; aircraft electrical parameter testing; linear fitting. The aircraft electrical parameter testing system can accurately test various parameters of the aircraft electrical network, thus providing a basis for the design of the aircraft electrical network. In general, aircraft electrical parameter testing systems are often composed of general-purpose PC industrial control computers as the core to form digital testing systems. These devices are relatively large, inconvenient to carry, and their reliability decreases in harsh environments. Therefore, there is a need for a convenient, compact, and fully functional testing instrument to complete field testing tasks. In today's information age, testing instruments have entered the era of intelligence. PC-based testing systems have become the mainstream in testing system development. These systems utilize the graphical display, peripheral interfaces, and software capabilities of PCs to complete testing tasks, while also ensuring the entire testing equipment is portable and compact. In this context, the PC/104 is undoubtedly an excellent choice. In terms of hardware and software, the PC/104 is fully compatible with the standard desktop PC (PC/AT) architecture. In terms of form factor, the PC/104 features a very compact, self-stacked, and modular structure. Numerous software and hardware resources are available for the PC/104, significantly shortening the development cycle. In the design of this tester, C language is primarily used to complete the design of data acquisition, data processing, data storage, and the final result display interface. For details, please click: Portable Aircraft Electrical Parameter Tester Based on PC/104