The invention provides an anti-interference electrocardiograph detection system, a detection method, a special flexible graphene electrode, and a preparation method and the application of the special flexible graphene electrode. The anti-interference electrocardiograph detection system comprises the flexible graphene electrode, an electrocardiosignal acquiring and processing module, an impedance measurement module, an electrocardiographic wire and a signal processing module, can measure an electrocardiosignal and a motion artifact signal, and removes the motion artifact in the electrocardiosignal. The flexible graphene electrode is formed in a way that a graphene material is adhered on a sponge layer through negative pressure deposition to obtain a graphene-sponge conductive composite, a fastener is additionally added on the graphene-sponge conductive composite, and the electrocardiographic wire is fixedly connected to the graphene-sponge conductive composite through the fastener. The anti-interference electrocardiograph detection system and the detection method effectively overcome the interference of the motion artifact on the electrocardiosignal, and guarantees the instantaneity, the accuracy and the reliability of the electrocardiographic examination result; the preparation flow of the flexible graphene electrode is simple, the biological compatibility of the flexible graphene electrode is good, the service life of the flexible graphene electrode is long, and the flexible graphene electrode can be used in the anti-interference electrocardiograph detection system.