提出了基于现代控制理论的空调动态负荷计算的新的谐波算法，论述了用状态空间法求取平壁热力系统的衰减度和延迟时间的原理和具体方法，与传统的基于经典控制理论的谐波法相比，避免了复杂的数学推导，易于计算机实现．实例计算表明，该方法效果良好． A new harmonic algorithm for dynamic load calculation of air conditioners based on modern control theory is proposed. The principle and concrete method for obtaining the attenuation and delay time of flat wall thermal systems using the state space method are discussed. It is compared with the traditional classical control theory. Harmonic method compared to avoid complex mathematical deduction, easy to computer implementation. The example calculation shows that this method works well.