Abstract: For the test nodes shortfall and the test variable conditionality in the analog circuit Multi-fault diagnosis, a analog circuit Multi-fault diagnosis method is brought forward based on node voltage increments. The equation of double-fault diagnosis is deduced using 4 test node voltage increments, and that the diagnosis flow and examples are explained in this paper. The theory analysis and the experimental result show that the new method can diagnose Multi-fault of linear circuits, and is effective hard-fault and soft-fault. The method has an advantage in the condition of the test nodes shortfall and the test variable conditionality, and adapts to large-scale linear analog circuit Multi-fault diagnosis and testing.