The invention provides a connection method for a micro-diameter electrode pin line and a stranded conductor. The connection method comprises the following steps that the stranded conductor is placed in a groove electrode tip, the micro-diameter electrode pin line is placed above the stranded conductor, an electrode tip pressing position is adjusted, welding pressure parameters of a resistance welding machine are provided, and the micro-diameter electrode pin line and the stranded conductor are pressed and shaped; welding parameters of the resistance welding machine are provided, the pressed and shaped micro-diameter electrode pin line and the stranded conductor are welded, wherein a pressing electrode tip is taken as a top electrode of the resistance welding machine, and the groove electrode tip is taken as a bottom electrode of the resistance welding machine; the width of a pressure head of the pressing electrode tip is smaller than the width of a groove of the groove electrode tip, and the height of the pressure head is greater than the depth of the groove. According to the technical scheme provided by the invention, the reliable connection between the micro-diameter electrode pin line and the stranded conductor can be simultaneously realized when the stranded conductor forms single-strand shaping.