As an efficiency-oriented product featuring strong adaptation, green energy saving and high performance, the XE200C hydraulic excavator is researched and developed on the basis of the market demands with the economic efficiency h ighlighted. This excavator uses an ISUZU engine excellent in energy conservation and environmental protection, an improved and optimized hydraulic system and an independently researched and developed control system, able to realize perfect matching of the power and efficiency and achieve low fuel consumption and high working performance (its working performance is leading among its peers); a buffer valve is configured, so that the complete control performance is good; its structural members have experienced computer-aided optimization design and 3D solid modeling design, so the enhanced working mechanisms can significantly improve the reliability and durability; the large-capacity fuel tank can enable the machine to work much longer at one time; the brand-new cab subject to injection molding features sufficient comfortableness, low noise and a beautiful appearance, as well as better warming and cooling effect by virtue of its new air-conditioning system. This machine is mainly applicable to municipal construction, highway bridges, housing construction, road engineering, construction of water conservancy works, port construction and other earthwork construction.