Diagnosis strategy is a testing sequence of the fault detection and isolation.For the distribution of the electronic equipment,a feasible engineering maintenance method is put forward based on the questions of test point selection and diagnosis strategy.The concepts of local diagnosis strategy and global diagnosis strategy are introduced.From which the local optimal diagnosis strategy is determined when the local optimal test points have been introduced by using the test information entropy,furthermore,the global optimal diagnosis strategy is determined by coalescing the local optimal diagnosis strategies.At last,the validity of the method is illustrated by an example from which the conclusion can be drawn that it is an optimal diagnosis strategy and the complexity of computation can be reduced.