The invention provides a planar representation method for transtension structures. The planar representation method comprises planar representation of the two-plate position, fault direction reversing, a relative motion direction of a single transtension fault, and a transtension ridge, a transtension groove and the combination pattern thereof formed by ground deformation and visually displays the two-plate position, fault direction reversing, the relative movement direction, the deformation characteristics of the stratum and the plane combination pattern. The invention can describe the basic geological characteristics of the transtension structure by two-dimensional graphics, and reflect the kinematic characteristics of the active plate, the relative movement direction, and the deformation characteristics easily neglected in the study; compared with the traditional extensional structure, the expression of strike slip structure is easier to distinguish and the characterization of transtension structures is more comprehensive, more reasonable and more systematic; the sketch map of the study area is more abundant in static information and the kinematics information is more reasonable; the expression of strike slip structure is beneficial to comprehensive and systematic understanding and expression of regional tectonic stress field.