To address the challenges of traditional MOSFET testing, such as cumbersome procedures, reliance on bulky instruments, and a low degree of intelligence, this paper presents an automated test system integrating a Large Language Model (LLM) with the "Yuzhu S" portable hardware. Centered around the "Yuzhu S" instrument, the system performs characteristic curve, switching time, and double-pulse tests using an integrated PCB carrier board. It innovatively leverages the Gemini API to empower the software, enabling automatic parsing of PDF datasheets, intelligent recommendation of test parameters, and in-depth error analysis of the results. The test results for an IRF7401 device demonstrate that the key static and dynamic parameters obtained by the system show excellent agreement with datasheet specifications and simulation values, thus validating the accuracy and feasibility of the proposed solution. This research provides an efficient, intelligent, and portable new method for end-users to evaluate device performance.