To enhance the automatic control precision and stability of thermal parameters (temperature, humidity, and air velocity) in Zanthoxylum bungeanum drying processes, improve the thermal uniformity of materials, and ensure drying quality, a fuzzy PID(proportional-integral-derivative) control system for parallel hot air-infrared pepper drying was designed with Siemens S7-200 PLC as the core controller. The system configuration incorporated EM235 and EM232 expansion modules, integrating temperature-humidity regulation, air velocity control, intermittent infrared tube rotation, and waste heat recovery subsystems. Through Simulink simulations in MATLAB, comparative analyses of control response characteristics between conventional PID and fuzzy PID controllers were conducted for temperature, humidity, and air velocity parameters. Experimental verification demonstrated that the fuzzy PID controller achieved maximum overshoot reductions of 6.39%, 21.71%, and 23.40% in temperature, air velocity, and humidity control respectively, with corresponding steady-state time reductions of 4.0 s, 4.7 s, and 5.9 s compared to traditional PID. During pepper drying trials, temperature stabilization at 60 ℃ was maintained within ± 0.4 ℃ error bounds, humidity control errors were constrained to ≤± 0.7%, and air velocity deviations at 2.0 m/s remained below ± 0.05 m/s. The system exhibited rapid response characteristics, stable operation, and high-precision control performance. Comparative evaluations against standard specifications and literature data confirmed superior quality in the experimental dried products. .