Aiming at the problem that the D matrix model based on single feature quantity can lose a lot of information about the test signal, a testability analysis model based on multifeature quantity is proposed. Firstly, based on the study of D matrix model, the feature extraction and multivalue coding of the test signal are carried out, and a D matrix model based on multifeature quantity is established. Then, the diagnostic strategies are developed based on the information entropy, the fault diagnosis tree is generated, and the model is analyzed to assess its diagnostic capabilities. The results show that the D matrix model based on multifeature quantity adopts a smaller number of test points and fuzzy group, and has a higher fault isolation rate, less diagnostic test step, and lower average test cost compared with the D matrix model based on the single feature quantity.