Railway equipment is critical for ensuring the safety of rail operations. Improving and evaluating the reliability of signal system hardware devices are crucial for the reliable operation of railway signaling systems. This chapter proposed a simulation collaborative design method for hardware products, which conducts coordinated simulation and design in various stages of R&D, including circuit principles, SI/PI, manufacturability, and thermal-structural-electromagnetic multi-physics fields, accompanied by numerous case studies. The simulation collaborative design development method applied to signal electronic equipment provided a basis for hardware product design optimization and evaluation, shortened the product development cycle, and effectively improved the reliability and safety of equipment.