Embedded CNC system has many advantages,but its system resources and processing capacity are limited.The trigonometric function acceleration/deceleration algorithm has the advantages of small flexible impact and high accuracy,but its calculation is complex,and it is difficult to meet the high real-time requirements of the system when applied to the embedded numerical control system.To solve this problem,an acceleration/deceleration algorithm was proposed.Based on the best square approximation,the polynomial function was used to approximate the trigonometric function,then the complete acceleration/deceleration equation was deduced and constructed.Then the speed planning of the algorithm under different conditions was analyzed.Finally,the algorithm was simulated and then tested on a CNC platform controlled by MCU.The results show that the algorithm reduces the computational complexity and improves the processing efficiency while preserving the flexibility of the trigonometric function curve.