In order to improve the reliability of the security and stability control system, this paper proposes some criterions against mal-operation which can prevent the no-fault trip’s misjudgment. Because the no-fault trip criterion is only based on local electrical quantities, it will misjudge when some disturbances occur. It researches the stability criterion of safety and stability calculation analysis and points out that we should design the criterions against mal-operations according to the specific problems. The no-fault trip criterion combined the proposed criterions against mal-operations has been widely used in the grid. Operation experience show that it can ensure the system’s timeliness and security, so the criterions against mal-operations are reliable.