A composite drill bit with a bit body configured at its upper extend for connection into a drillstring, comprising: a bit body (1) with at least one bit leg (3), at least one scraping-wheel (2) set with a cutter-row (4), and a set of cutters fixed thereon. The scraping-wheel (2) is mounted for rotation on the corresponding bit leg (3) with a large angular deflection α in the range of 20°≦|α|≦90°. The cutters on the scraping-wheel break rock by means of successive scraping, forming a cross-cutting area on the bottomhole accompanied by the cutters on the fixed cutting unit, thus achieving high rock-breaking efficiency, even wear, high cooling performance, and a longer service life for the cutters, bearings and the drill bit.