Failures in starring circuit of model wy1 . 5 hydraulic excavator are tested and analyzed . potential defects in circuit design are found out . some simple and feasible countermeasures of improvement are suggested 摘要对wy1 . 5型液压挖掘机的启动电路的故障进行了检测和原因分析,找到了电路设计中潜在的缺陷,并提出了简单易行的改进措施。