In order to utilize the wavefront curvature sensor in the field of laser wavefront theoretical analysis for the signal of wavefront curvature sensor under the illumination of nonuniform intensity is made. By means of Fresnel diffraction, signal of wavefront curvature sensor is computed under the conditions that the first 10 Zernike polynomials phase profile, and Gaussian distribution or normal random distribution intensity profile, and then compared with the signal with the same phase profile but uniform intensity profile. Analysis indicates that nonuniform intensity introduces some error into wavefront curvature sensor signal. Intensity of Gaussian distribution impacts significantly the sensing signal of the defocus phase, in which the error percentage achieves 25%, but for other phase profile, the effect is ignorable. Illuminated by the normal random scintillation, there is a linear relation between the error percent and the root mean square of the normal random distribution. Under some given conditions, the wavefront curvature sensor also can be utilized in the field of illumination of nonuniform intensity.