When intense infrared laser and extreme ultraviolet (XUV) attosecond pulse interact with an atom or molecule, the released electrons generally suffer a spread of energies due to the absorption and emission of laser photons. The nondipole effects in the high-order harmonic generation caused by the short wavelength of XUV attosecond pulse which is comparable to the scale of spreading electron wavepacket are discussed in this paper. The H+2 ion as a model molecule is assumed to be aligned along the propagation direction of the laser field. By solving the two-dimensional time-dependent Schrdinger equation and comparing the results taking account of nondipole effects with those under the dipole approximation, we find that intensity of the former harmonic yield is lower than that of the latter with a shift of the frequency towards lower order harmonics, and that more photoelectron peaks appear in the energy band of the photoelectron spectrum and the difference of their signal intensity at the same photoelectron energy is 2—5-fold. The results of numerical simulation also show that the nondipole effects are enhanced with the infrared laser field strength increasing and are weakened with the wavelength of attosecond pulse increasing.