In the common path/common mode(CP/CM) adaptive optics(AO) system,two Hartman-Shack (H-S) wavefront sensors are used to realize the aberration sensing in the whole light path,controlling of a set of wavefront corrector and compensation of the aberration in the whole light path. Here the data fusion methods of the two H-S sensors in the CP/CM AO system are studied and the effects of the disturbance of the vector of slope data and the Reconstruction matrix to the controlling voltage are analyzed through the condition number of the reconstruction matrix. Corresponding formula are given. The close loop experiment of CP/CM is achieved. Modified slope and voltage data fusion methods are suitable to the engineering under the exising technology condition. They are equivalent in the finding of the controlling voltage, but the wavefront processors will be different.