分别从单自由度系统、双自由度系统以及多自由度系统角度，分析了弹簧隔振基础的隔振效率。采用双自由度振动方程对隔振效率进行了理论推导，得出位移之比隔振效率的理论公式；采用振动方程与有限元分析相结合的方法，得出单自由度系统总体平均隔振效率数值偏高，双自由度系统总体平均隔振效率接近于有限元分析结果，转子扰力相位对隔振效率计算有影响，实际工程设计可采用平方和开平方（square root of the sum of squares，SRSS）方法求得隔振效率。

The vibration isolation efficiency of spring vibration-isolation foundation is analyzed with single degree of freedom (SDOF) system, two-degree of freedom system and multi-degree of freedom system. The displacement theoretical formula of the isolation efficiency is deduced with two-degree of freedom vibration equation. It is concluded through vibration equation and finite element analysis that the general average isolation efficiency of the single degree of freedom system is on the high side, while the general average isolation efficiency of two-degree of freedom system is close to the finite element analysis result; the nominal unbalance phase has some effects on the calculated isolation efficiency and the square root of the sum of squares (SRSS）method can be used to calculate the isolation efficiency in actual engineering design.