A stable conductive myocardial patch with a negative Poisson's ratio structure is provided. The preparation method includes preparing a myocardial patch substrate with concave polygons as the structural units by weaving or knitting, and then a conductive coating is coated on the surface of the substrate. Alternatively, the yarns can be processed into conductive coated yarns first, and then used as the raw material to weave or knit a stable conductive myocardial patch with a negative Poisson's ratio structure. The prepared myocardial patch has a relative resistance change of less than 5% at 50% tensile strain. When the strain of the structural units is within 50%, the fabric exhibits a negative Poisson's ratio structure, which expands in the perpendicular direction of the tensile load. The fabric exhibits a negative Poisson's ratio effect and anisotropy of Young's modulus, which matches the mechanical behavior of natural myocardium.