The invention protects a self-adjusted straight-through strain fitting, comprising a bracket part and a straight-through outward-extending arm fixed to the bracket part. Both ends of the straight-through outward-extending arm are connected to self-adjusted wire clamps through spherical hinges. A power transmission wire is connected to the self-adjusted wire clamps. The self-adjusted straight-through strain fitting is used for a composite cross-arm. A tensile tower can be connected with the wire by the same type of connection components and metal fittings within a 0 to 60-degree angle range bya conductive adaptive angle way, and complex metal fittings such as insulator strings and jumpers in a conventional cross-arm are removed so as to greatly simplify the connection design of wires and the tensile tower, reduce cost, and improve processing and installation efficiency.