The invention discloses a cadmium zinc telluride (CdZnTe) X-ray detector for nitrogen thermoelectric cooling. The outside of a CdZnTe detector is provided with a shielding case. A hole is disposed in the shielding case and covered with a double-sided opaque aluminum laminated film. The inside of the shielding case is provided with a thermoelectric cooler. The thermoelectric cooler cools a constant low temperature drive circuit through an external cooler. The CdZnTe detector in the shielding case receives and converts an X-ray into a charge signal, and obtains an ideal nuclear pulse signal after the amplification through a reset type charge sensitive amplifier. The invention has the beneficial effects of eliminating current noises brought by a discharge resistor, improving the signal to noise ratio, and effectively improving the energy resolution of the system.