Horizontal well mode is more and more widely used in low permeability reservoir development and reasonable parameters must he selected in order to obtain the optimum yield-increasing effect during horizontal well fracturing. Applied is orthogonal experiment method to conduct optimization study on horizontal well fracturing parameters and in numerical simulation model, characteristics of low permeability oilfield are accurately reflected by application of threshold pressure since it can replace start-up pressure gradient. Through range analysis on cumulative oil production of different experimental schemes, obtained are the primary and secondary effects of different fracture parameters on cumulative oil production during horizontal well fracturing and the sequence of such effects is: the number of fractures, the length of the horizontal well, the lengthwise position of horizontal sections and the length of fracture. The optimal level values of fracturing parameters are respectively: the number of fractures is 5, the length of horizontal section is 400m, the lengthwise position of horizontal sections is the third layer and the length of fracture is 240m.