The fault diagnosis has become an increasing portion of today's IC-design cycle and significantly determines product's time-to-market. However, the failure behaviors from the defective chips may not be fully represented by the single fault model. In this paper, we propose a fault-diagnosis framework targeting multiple stuck-at faults. This framework first reports a minimal suspect region, in which all real faults are topologically covered. Next, a proposed ranking method is applied to sieve out the real faults from the candidates within the suspect region. The experimental results show that the proposed diagnosis framework can effectively locate the multiple stuck-at faults within a neighborhood, which may generate erroneous signals cancelling one another and are difficult to be diagnosed based on a single-fault-model method.