The invention relates to a building method of a collaborative anchoring duplex structure of a thick layer composite roof coal roadway, and belongs to the technical field of coal mining. The problems of large control difficulty and high cost of an existing thick layer composite roof coal roadway are solved. The building method includes the following steps: first, a geological radar is adopted to detect the loose ring range of a thick layer composite roof of a coal roadway, the multi-stage anchoring structural area range and the length of an anchoring rod are determined; second, the anchoring rod is mounted in a drilled mode at shallow sounding rock of a roof of a newly excavated section to form a shallow anchoring structure; third, a medium-length anchor cable is mounted in a drilled mode to form a shallow layer and medium-deep layer anchoring structure; and fourth, a long anchor cable is mounted in a drilled mode to form the shallow layer, medium-deep layer and deep layer collaborativeanchoring duplex structure. The stability of the sounding rock of the thick layer composite roof is effectively controlled, and safe, economical and efficient production of a coal mine is promoted.