The　Fourier　transform　spectrometer　is　based　on　a　scanning-type　Michelson　interferometer　with　two　optical-beams　including　reference　laser　and　measurement　light.　The　optical　spectrum　of　measurement　light　can　be　obtained　by　colleting　the　analog　signal　of　measurement　light　with　the　sampling　time-scale　based　on　interference　fringes　pulse　of　reference　laser.　The　optical　interferogram　signal　of　the　reference　laser　is　converted　to　pulse　signal,　and　it　is　subdivided　into　16　times.　So　the　sampling　rate　is　constant　only　depending　on　frequency　of　reference　laser　and　irrelative　to　the　scanning-motor　velocity.　This　means　the　sampling　rate　of　measurement　channel　signal　is　on　a　uniform　time-scale.　In　order　to　get　optical　spectrum,　the　analog　signal　of　measurement　channel　should　be　collected　and　Fourier-transformed.　Digital　Signal　Processor　(DSP)　TMS320-F2812　is　used.　Its　internal　12-bit　Analog-to-Digital　Converter　(ADC)　for　measurement　channel　is　triggered　by　the　16-times　pulse　signal　of　reference　laser.　The　DSP　is　used　to　process　optical　interferogram　signal　with　ADC　sampling　rate　up　to　about　1.5MHz.　The　optical　spectrum　of　measurement　channel　signal　is　processed　with　1024　points-Fast　Fourier　Transform　(FFT)　method.　Then,　the　ZOOM-FFT　is　adopted.　By　digital　frequency-shift　conversion　and　low-pass　filter,　these　digital　signals　are　processed　with　1024　points-FFT　once　again　to　improve　the　frequency　measurement　resolution.　Finally,　the　optical　spectrum　of　measurement　channel　will　be　displayed　on　LCD　with　high　frequency-resolution.