A multispectral photography of white-light optic/digital image processing with θ-multichannel modulator is brought forward, in which θ-multichannel modulator is used to modulate the several waveband information of the object, and the technique of Fourier transform is employed to decode the modulated image, then waveband information of the object is demodulated. Afterwards, a multispectral pseudo-color image can be obtained by means of pseudo-color fusion. A new multispectral system consists of θ-multichannel modulator and a single CCD. And it provest to be feasible to substitute the new system for traditional one composed by several cameras with different bands. Compared with the traditional multispectral photography system, the new one has many advantages, such as small volume and weight, easy operation in pseudo-color fusion.