According to the safety and control requirements of the excavator reconstruction project of PetroChina, a drilling and digging integrated excavator was designed with hydraulic energy saving and safety control as the core automation equipment for pipeline construction. According to the design requirements of excavator transformation, a mechanical structure of drilling and digging integrated excavator construction equipment based on PLC control was designed. On the basis of the common excavator, Delta AS228T-A PLC was connected with the external actuator, and the signal acquisition was carried out by RS485 serial port communication, and the corresponding sensor was controlled by PLC for data processing in real time. At the same time, the PLC D/A analog output module and VT3000 proportional amplifier were used to control the variable plunger pump. The current size of pump 1 and pump 2 was controlled respectively to solve the trouble caused by the failure of one way during the operation, to ensure that the two functions of digging and drilling can be carried out normally, and effectively improve the work efficiency.