Structure parameters of the slow light in the photonic crystal coupled resonator optical waveguide have been investigated. It is found that cavity distance n,filling factor r/a and size of the defect rod rd are the most significant factors affecting the transmission properties of the slow light guided mode in the photonic band gap. With the increase of cavity distance,the group velocity vg of guided mode decreases rapidly. When filling factor and defect rod size increase,the guided mode shifts towards a lower frequency with vg decreasing simultaneously. When the filling factor and defect rod size increase to a respective certain value,vg reaches a bottom value. And as r and rd exceeds the above certain value,group velocity of the guided mode will increase. By choosing appropriate structure parametersm of n=6,r=0.22a,rd=0.12a,it is obtained that the maximum value of guided mode vgmax=1.93×10-3 c and vg<10-4 c at the band edge in the photonic crystal coupled resonator optical waveguide. These results indicate that effective control over the slow light in the photonic crystal coupled resonator optical waveguide could be realized through basic structure design,which may offers significant support for design and application of functional devices based on photonic crystals.