The complex working status requires construction machinery having higher reliability. Using the interrelationship between fault phenomena and fault causation, and display simulation bar on LCD, sounding and lighting Mann, the fault tree of gear shift and engine of construction machinery was established on the basis of the expert system. A remote network monitoring and diagnosis system based on Virtual Instruments is presented and the method of remote network monitoring and fault diagnosis based on LabVIEW is given. The functions of fault returning checking, fault re-displaying, fault inquiring, and LCD auto-adjusting are carried out. The research result will be an effective measure of improving system reliability of fault diagnosis of construction machinery.