Four kinds of guest-host adulterate thin films were prepared by using spin-coating method, and then their thickness, refractive index, UV-Vis spectra and the signal of second harmonic generation (SHG) after all-optical poling were measured. The experimental result was shows that the value of SHG depends on the dipole property of azobenzene molecule for the same thickness, and the stronger the dipole property of azobenzene molecule is, the bigger the value of SHG is. Calculation result shows that the nitryl (-NO2) connected with benzene has the biggest second-order nonlinear optical coefficient d33 that equals to 4.97×10-1 pm/V, and the weakest equals to 2.55×10-2 pm/V. It can be explained in theory that different dipoling induces the different excitation extent for these azobenzene molecules. This work can offer a powerful experimental help to the design of molecular materials.