The invention provides a decoupled tri-rotation parallel mechanism, which comprises a stand, a moving platform, a first moving branch chain, a second moving branch chain and a third moving branch chain, wherein the first moving branch chain, the second moving branch chain and the third moving branch chain are connected between the stand and the moving platform. The first moving branch chain comprises a first universal hinge, a first moving pair and a second universal hinge which are sequentially connected; the second moving branch chain comprises a first spherical hinge, a second moving pair and a second spherical hinge which are sequentially connected; and the third moving branch comprises a rotation pair and a third universal hinge which are sequentially connected. The invention has three decouple rotational degrees of freedom, and the rotational freedom degree of freedom only depends on the linear control of the moving pair of the moving branch chains, therefore, the implementation principle is very simple and the mechanism has quite good linear relation.