A generalized morpho-interpolation method for nonrigid body motion is proposed based on morpho translation. The problem of morpho-interpolation between two nonhomotopy polygons (including concave polygon and holey polygon) is solved by decomposing polygon into several individual convex subpolygons and constructing the matching of two convex subpolygons. It is proved that nonrigid body motion can be divided in to the composing of nonrigid body metamorphosis and rigid body rotating. The principle of the morpho-interpolation is also proved and the effects of morpho-interpolation with different convex decomposing are discussed. Experimental results show that this method can get the natural, higher quality metamorphosis sequence with simple computation and can be used in description of nonrigid body motion and automatically interpolation between two deyframes in 2D animation.