The invention discloses an active and passive dual-mode 
spectrometer, which is composed of two parts inside and outside a 
fuselage.  Among them, there are two-in-one 
optical fiber, interface, slit and main controller outside the 
fuselage; the inside of the 
fuselage contains electric stage, active converging mirror, 
prism, active collimating mirror, active 
blazed grating, passive 
blazed grating, 
grating bracket, column  Converging lens, linear variable filter, back-illuminated array 
detector, array drive circuit, passive converging mirror, passive collimating mirror, exit slit, shading screen, 
photomultiplier tube, motorized scanning table, scanning controller,  working circuit.  The beneficial effect of the present invention is that, by adopting ingenious electromechanical switching and 
grating area splitting, the internal structure of the 
spectrometer can be optimized, and the compactness and convenience of the 
system can be improved; the same 
spectrometer and the same 
optical fiber inlet can realize the composite detection of active and passive spectra, and improve the detection efficiency.  Efficiency: According to the different characteristics of active and passive spectra, different designs are adopted at the sensor end to achieve targeted spectral detection, improve active 
spectral resolution and passive spectral 
signal-to-
noise ratio.