The invention provides a frame-type design method of an instrument system for spectrum analyzers, which comprises the following steps that: firstly, abstract analysis on the requirement of an apparatus software is carried out, then functional partitioning is carried out on the base of requirement analysis, and then the data analysis and the behavioral analysis are carried out to obtain an abstract instrument model. The model is divided into an abstract layer and a specific project realizing layer, wherein the abstract layer describes the standards and guidelines of various behaviors required by users only from the requirement analysis angle, and the specific project realizing layer focuses on ways to meet the requirements of the users. Based on common abstraction, the system can be divided into six modules according to the usage, namely a command module, a function execution module, a display module, an algorithm module, an information management module and an auxiliary function module, the object-oriented design idea is developed after the model is obtained, therefore, the coexistence of the commonalities and the differences can be achieved.