Abstract: The present invention discloses a spherical-screen device, a spherical-screen playing system and an image generating method thereof, which adopt the following steps for image rectification: equally dividing an arc curve of a spherical screen, which corresponds to a radian of 90°, into a plurality of segments; according to pixels of a planar image that needs to be displayed, equally dividing a straight line of the planar image corresponding to the arc curve into a plurality of segments, the number of the segments of the straight line being equal to the number of the segments of the arc curve; assigning an image parameter of a first point in the planar image to a third point in a planar image; and connecting a sphere center with a second point of a to-be-displayed image position on the arc curve that corresponds to the first point, a point falling in the planar image being the third point.