Permanent magnet brushless DC motors (BLDC) are extensively utilized across various industries due to their high efficiency, reliability, low noise, and superior power density. Designing a precise and rapid speed control system for BLDC motors is crucial for expanding their application scope. This paper investigates the speed control principles of BLDC motors, highlighting the implementation of a dual closed-loop PI control system. Using the Matlab/Simulink simulation platform, a comprehensive model is developed to evaluate the performance under no-load startup, speed variation, and sudden load application scenarios. The simulation results demonstrate that the proposed control system offers robust speed regulation, rapid response, and strong disturbance rejection capabilities. Further analysis and comparison with other control methods are recommended to establish its relative advantages.