The invention relates to a centering rotating type semi-portal truss applied to a stacker-reclaimer for a circular stock yard and belongs to the technical field of stacking and reclaiming equipment for bulk materials in circular stock yards. The truss comprises a centering rotating part, a rotating portal part in rotating connection with the centering rotating part used as a rotating pivot as well as a bucket wheel reclaiming part connected onto the rotating portal part in a liftable manner; the bucket wheel reclaiming part can rotate with the rotating portal part; when the rotating portal part rotates around the centering rotating part, and the bucket wheel reclaiming part is driven to reclaim materials in a liftable manner, so that a reclaiming part and/or a stacking part of the stacker-reclaimer can be driven to rotate together, and reclaiming and/or stacking of the circular stock yard can be realized; through optimization of the structure of the semi-portal truss, co-rotation arrangement of a bucket wheel machine and a belt conveyor fixed on the semi-portal truss can be met, the portal stacker-reclaimer of the circular stock yard adopts bucket wheel type reclaiming, and the reclaiming productivity of stacking and reclaiming of the circular stock yard is improved.