Fabricated reinforced concrete columns are important components of reinforced concrete structures. During the design reference period, columns are prone to degradation in mechanical and deformation properties, which affects the normal service of the structure. Based on compressive tests of fabricated reinforced concrete columns, this paper uses ABAQUS 2021 finite element analysis software to explore how factors such as column damage and CFRP sheet layout affect the compressive performance of fabricated concrete columns under eccentric compression in order to investigate their mechanical properties and the confinement effect of CFRP sheets on such columns. The results indicate that the change trend of the bearing capacity of the finite element model is largely in agreement with that of the test specimens, and the ultimate bearing capacity error is below 3%, thereby confirming the validity of the finite element model. Compared with strip confinement, full-wrap confinement achieves a greater improvement in ultimate bearing capacity, and two to three layers are recommended as the ideal number of CFRP sheets for strengthening. The maximum increase in ultimate bearing capacity can reach 19.18%. When the strip width is constant, the smaller the spacing, the smaller the concrete strain in the compression zone. When the net spacing is constant, reducing the strip width increases the number of cracks and decreases crack width, but reduces the ultimate bearing capacity of the column accordingly. Strengthening with CFRP sheets can enhance the ultimate bearing capacity, deformability, and ductility of columns with initial damage under both small and large eccentric compression. The maximum increase in ultimate bearing capacity can reach 8.31%. The results obtained in this paper are conducive to promoting the reinforcement and reconstruction of fabricated reinforced concrete columns and reinforced concrete structures.