This study examines the effect of polyester multifilament oil, mill absolute humidity, and the effect of spreading voltage on multifilament spread width on properties of composite yarn. The results show the yarn spinnability and properties can be improved by the correct selection of oil type with oil contents at 0.7%, by controling absolute humidity and by adjusting spreading voltage to stabilize spread width at about 8∼10 mm. In addition, it can be increased about 30% in production with low twist and still retain excellent yarn properties; especially on a high tenacity, low imperfection index and only about 10% hairiness when compared with cotton‐rich spun yarn.