Prefabricated concrete frame structure refers to a concrete structure constructed entirely or partially using prefabricated components for frame beams and columns. This article studies the parametric modeling of prefabricated concrete frame structures. Using existing flat construction drawings, the geometric and reinforcement data of the components are extracted, and a three-dimensional parametric model containing the reinforcement data of the components is established. The code based on PSO (Particle Swarm Optimization) and GA (Genetic Algorithm) is written to solve and achieve automatic arrangement of steel bars in the beam column node area. The test results show that GA can significantly improve the efficiency of automatic steel bar layout.