The present invention is related to a Cisd2 knockout mouse with phenotype comprising mitochondrial breakdown and dysfunction, wherein Cisd2 is defined as SEQ ID NO. 1. The present invention is also related to a mouse model of Wolfram Syndrome 2 (WFS2) disease consisting of a Cisd2 knockout mouse. The present invention is further related to a method for screening a candidate agent for preventing or treating WFS2 disease.