Previous studies have indicated that precast concrete columns reinforced by efficient reinforcement exhibit favorable static and seismic performance at room temperature; however, their post-fire mechanical behavior has not been thoroughly investigated. This study conducted residual mechanical performance tests on ten full-scale precast concrete columns reinforced by efficient reinforcement and five comparative ordinary reinforced concrete columns after exposure to fire. The study parameters included reinforcement forms, duration of fire exposure, and cross-sectional dimensions. Each column was subjected to the ISO 834 standard fire, allowed to cool, and then tested under axial compression. The experimental findings revealed that the connection regions of the precast concrete columns maintained adequate strength after fire, with failures predominantly observed in the non-connection areas. An increase in fire exposure duration resulted in a notable decline in the load-bearing capacity and stiffness of these columns. After exposure to fire, the precast concrete columns reinforced by cluster reinforcement exhibited higher load-bearing capacity, axial stiffness, and ductility compared to columns reinforced by large-diameter reinforcement, whose performance was comparable to that of the ordinary reinforced concrete columns. Based on the test results and existing calculation methods, a simplified approach that considers the effect of reinforcement forms was proposed to predict residual load-bearing capacity of precast concrete columns reinforced by efficient reinforcement after fire.