The utility model discloses a novel single-circuit tee-joint transmission tower and relates to the technical field of high-voltage transmission lines. The single-circuit tee-joint transmission tower comprises a tower body, a wire cross arm, a tee-joint auxiliary cross arm, a main line insulator chain and a tee-joint line insulator chain. The wire cross arm and the tee-joint auxiliary cross arm are arranged on the tower body; the tee-joint auxiliary cross arm is arranged below the wire cross arm; the included angle between the tee-joint auxiliary cross arm and the wire cross arm is 90 degrees; the main line insulator chain is arranged on the wire cross arm; and the tee-joint line insulator chain is arranged on the tee-joint auxiliary cross arm. Compared with the common single-circuit tee-joint transmission towers, a main line wire of the novel single-circuit tee-joint transmission tower disclosed by the utility model remains triangular arrangement, suspension strings of adjacent towers at two sides of a tee-joint tower remain vertical, electric clearance of a tower head keeps meeting the original rule design requirements, changing an adjacent tangent tower to a strain tower is avoided, the number of newly-built towers is reduced and the construction cost is saved.