The invention discloses a testing method and device for reliability of an information system. The testing method comprises the following steps: taking all system nodes in the information system as target nodes in sequence, setting the target nodes to be fault states, and setting all system nodes except the target nodes to be normal operation states; judging whether system functions of the information system are abnormal or not when each of the system nodes is used as the target node; if the system functions of the information system are all normal when all the system nodes are sequentially used as the target nodes, judging that no single point potential hazard exists in the information system; and if the system functions of the information system are abnormal when all the system nodes aresequentially used as the target nodes, judging that the single point potential hazard exists in the information system. According to the testing method, by the mode of judging whether the system functions are abnormal or not through the self-set fault nodes, the single point potential hazard in the information system is tested, so as to test the reliability of the information system; compared witha mode of manually testing the reliability of the information system, the mode greatly improves the testing efficiency and accuracy.