A uniformly-partitioned high-precision sub-reflector device with a two-stage position and pose adjustment function, comprising an adjustment device, a sub-reflector, a single-layer space frame backup structure and a panel precise adjustment device; wherein the adjustment device is located in a direction of an aperture of the sub-reflector and comprises a movable platform, a fixed platform, a primary adjustment rod, an auxiliary adjustment rod, a movable platform spherical joint and a fixed platform spherical joint; the movable platform is connected to the single-layer space frame backup structure, and the fixed platform is located outside the aperture of the sub-reflector; the fixed platform is a plane truss structure with an N-polygonal shape, wherein N is a natural number and N≥4; the fixed platform is composed of N fixed platform rods (1-2-1 to 1-2-N), every two of which are connected by the fixed platform spherical joint; the movable platform is a plane truss structure with a 2N-polygonal shape, and is composed of 2N movable platform rods (1-1-1 to 1-1-2N), every two of which are connected by the movable platform spherical joint; the movable platform rod (1-1-1 to 1-1-2N), the fixed platform rod (1-2-1 to 1-2-N), the primary adjustment rod and the auxiliary adjustment rod form a mesh structure with a plurality of triangular space regions; the sub-reflector is composed of an N-polygonal panel and N sectorial panels, with the N sectorial panels being radially distributed around the N-polygonal panel and each having an area substantially equal to that of the N-polygonal panel, and the sub-reflector being connected to the single-layer space frame backup structure through the panel precise adjustment device; the single-layer space frame backup structure is composed of an inner ring support, a main rod, a diagonal rod and an inner ring spherical joint; wherein the inner ring support has an N-polygonal shape and is composed of N inner ring rods (3-1-1 to 3-1-N), every two of which are connected to each other through the inner ring spherical joint; the inner ring rod, the movable platform rod (1-1-1 to 1-1-2N), the main rod and the diagonal rod form a mesh structure with a plurality of triangular space regions; the panel precise adjustment device comprises a positioning mechanism and an adjustment mechanism, with the positioning mechanism being located at connection points between the N-polygonal panel and the inner ring spherical joint of the single-layer space frame backup structure, and connection points between the N sectorial panels and the inner ring spherical joint of the single-layer space frame backup structure; and the adjustment mechanism being located at a non-working side of an antenna panel. wherein the adjustment device is located in a direction of an aperture of the sub-reflector and comprises a movable platform, a fixed platform, a primary adjustment rod, an auxiliary adjustment rod, a movable platform spherical joint and a fixed platform spherical joint; the movable platform is connected to the single-layer space frame backup structure, and the fixed platform is located outside the aperture of the sub-reflector; the fixed platform is a plane truss structure with an N-polygonal shape, wherein N is a natural number and N≥4; the fixed platform is composed of N fixed platform rods (1-2-1 to 1-2-N), every two of which are connected by the fixed platform spherical joint; the movable platform is a plane truss structure with a 2N-polygonal shape, and is composed of 2N movable platform rods (1-1-1 to 1-1-2N), every two of which are connected by the movable platform spherical joint; the movable platform rod (1-1-1 to 1-1-2N), the fixed platform rod (1-2-1 to 1-2-N), the primary adjustment rod and the auxiliary adjustment rod form a mesh structure with a plurality of triangular space regions; the sub-reflector is composed of an N-polygonal panel and N sectorial panels, with the N sectorial panels being radially distributed around the N-polygonal panel and each having an area substantially equal to that of the N-polygonal panel, and the sub-reflector being connected to the single-layer space frame backup structure through the panel precise adjustment device; the single-layer space frame backup structure is composed of an inner ring support, a main rod, a diagonal rod and an inner ring spherical joint; wherein the inner ring support has an N-polygonal shape and is composed of N inner ring rods (3-1-1 to 3-1-N), every two of which are connected to each other through the inner ring spherical joint; the inner ring rod, the movable platform rod (1-1-1 to 1-1-2N), the main rod and the diagonal rod form a mesh structure with a plurality of triangular space regions; the panel precise adjustment device comprises a positioning mechanism and an adjustment mechanism, with the positioning mechanism being located at connection points between the N-polygonal panel and the inner ring spherical joint of the single-layer space frame backup structure, and connection points between the N sectorial panels and the inner ring spherical joint of the single-layer space frame backup structure; and the adjustment mechanism being located at a non-working side of an antenna panel.