Composite bow

The invention relates to a composite bow which comprises a bow handle, a bow piece, a pulley block, a main chord, a first coupler, a second coupler, a first auxiliary cable and a second auxiliary cable, the pulley block comprises a main chord wheel, a first auxiliary cable wheel and a second auxiliary cable wheel, and the first auxiliary cable wheel and the second auxiliary cable wheel are arranged on the two sides of the main chord wheel respectively. The first coupler can couple or decouple the first auxiliary cable wheel and the main chord wheel at a set position, and the second coupler can couple or decouple the second auxiliary cable wheel and the main chord wheel at a set position. The two sets of auxiliary cable wheels are arranged, in the single shooting cycle (full drawing-releasing), the different auxiliary cable wheels are switched to be coupled with the main chord wheel, conversion of the tension characteristic curve of the pulley block in the single shooting cycle is achieved, and the tension cha