The failure modes of electronic systems are various due to the complex functional structure and operation under complex environmental conditions of multiload coupling. Therefore, the malfunction of the electronic system can be regarded as the result of the mutual combination of multiple failure modes. At present, there are few reliability modeling methods considering the multimode coupling of electronic systems. This paper studies the reliability modeling method under the condition of multimode coupling of the electronic system. First, each failure mode's life distribution information is obtained through the reliability simulation analysis method based on the physics of failure. Then the Copula function is utilized to establish the reliability model of the multimode coupling system, and the reliability calculation method is given. Finally, a case study of a specific type of integrated electronic system shows that the method proposed in this paper can achieve more accurate calculation results of reliability, and avoid overly conservative in reliability assessment.