The invention discloses an inserted plate connection assembly and a power transmission line steel pipe tower. The inserted plate connection assembly comprises two gusset plates and two inserted plates, wherein the two gusset plates are arranged in a cross shape to form a gusset plate joint; the two inserted plates are arranged in a cross shape to form an inserted plate joint; the gusset plate joint and the inserted plate joint are abutted by a connection component through a fastener; the connection component comprises two, three or four bent plates; and two bent plates are symmetrically arranged relative to the center of the inserted plate connection assembly. The inserted plate connection assembly disclosed by the invention realizes the advantages of simple connection, high structure stress coordination, strong stability and sufficient stress of angle iron or the bent plates.