The invention discloses a horizontal type turning and milling composite processing center, which comprises a base (71), an upright post (63), an X-axis guide rail, a Z-axis guide rail, a Y-axis guide rail and a cutter assembly. The cutter assembly comprises a C-axis swing head component (82) moving around the Y-axis direction and a B-axis swing head component (81) moving around the X-axis direction. The B-axis swing head component (81) is connected to the end part of the C-axis swing head component (82) through a quick-change connector component and a fastening bolt. The B-axis swing head component (81) is a B-axis swing head component of which lower end cutter is set into a right-angled milling head of 90 degrees or a B-axis swing head component of which lower end cutter is set into a right-angled cutter head of 90 degrees with turning and milling functions. The invention aims to provide the horizontal type turning and milling composite processing center which has the function of a common turning and milling composite machine, can be used as special processing equipment for blades and achieves the aims of one machine with multiple purposes and manufacturing cost reduction.