The invention provides an export protection method and device applicable to a double-CPU (central processing unit) structure, wherein one CPU receives starting criterions of the other CPU; when the starting criterions and action criterions of the CPU and the received starting criterions of the CPU are met at the same time, the export tripping is performed. The method and the device have the advantages that the maloperation due to protection device hardware fault can be well avoided; in addition, the realization method is simple and reliable; the generator-transformer unit protection reliability can be improved.