Using the fuzzy design theory, the safety factor of bolts for cylinder head is judged fuzzily based on considering the design, manufacture, material and using condition. An example is given.

• 摘要运用模糊设计理论，在考虑了设计水平、制造水平、材料性能和使用等因素的基础上，对柴油机气缸盖螺栓的安全系数取值大小进行了模糊综合判断，并给出了一个例子。