Abstract: The large radio telescope has extremely high system sensitivity, and the electromagnetic protection requirements for its own electronic equipment are also very high. As a result, there are technical challenges in the final shielding effectiveness measurement and performance verification. The study of relevant technologies provides technical support for the implementation of electromagnetic compatibility engineering for the telescope. To address the technical issues associated with multi-scenario shielding measurement in telescope construction, this paper analyzes the main factors affecting shielding effectiveness measurement. Based on the GB/T 12190-2021 “Method for measuring the shielding effectiveness of electromagnetic shielding enclosures”, a measurement system was constructed in a 3 m darkroom. Systematic measurements were conducted around the hardware chain of the measurement system and the response relationship between key parameters of the signal analyzer and the shielding effectiveness measurement performance. Based on this, we conducted a statistical analysis of its impact on the performance of shielding effectiveness measurements. Using the electromagnetic shielding classification method in GJB 5792A-2021 “Classification and measurement methods for electromagnetic shielding enclosures of military security information system”, we planned the shielding effectiveness measurements into four scenarios. We then provided corresponding hardware and measurement parameter configuration strategies for each shielding effectiveness measurement scenario. We built and tested systems for measuring shielding effectiveness according to different strategies, further verifying the feasibility of these configuration strategies in different scenarios.