The invention relates to a windage yaw-proof Y-type composite insulator, which comprises an I-shaped composite insulator string. The windage yaw-proof Y-type composite insulator is characterized by further comprising a strut type composite insulator string. The middle part of the I-shaped composite insulator string is fixedly provided with a connecting piece. One end of the strut type composite insulator string is fixed onto the connecting piece through a fastener, and the other end of the strut type composite insulator string is installed on a tower cross arm through a fixing piece. According to the technical scheme of the invention, on one hand, the strut type composite insulator string is arranged on one side of the I-shaped composite insulator string that is closer to a tower body so as to form a branch and construct a fixed triangular support, so that the swing of the I-shaped composite insulator is effectively limited. In this way, the windage yaw-proof Y-type composite insulator is simple in structure, convenient in operation and high in practicability. On the other hand, compared with a V-string insulator, the size of a cross arm is not increased and the structure of a tower head is not changed. Therefore, the expenditure can be saved to the greatest extent.