Abstract: The complex fracturing technique is a new kind of stimulation technique hich can combine high energy gas fracturing with conventional hydraulic fracturing. This paper discussed the fracture initiation mechanism of complex fracturing technique, gave the design criteria of it and analyzed the effect of the technique on casing and cement. And the application effect was also analyzed. The field test of 33 wells showed that the technique had advantages of less additional cost, obvious effect of stimulation and small technical risk and so on, it is.an effective measure which can improve low-permeability oil-gas reservoir.