Aiming at the problem of signal floating and non-consistency of the three-stage thermoelectrically cooled photoconductive (PC) HgCdTe Infrared detectors，the causes are analyzed and studied.The necessity of output consistency and signal stabilization is pointed out.This paper focuses on the influence of adjusting the bias current on the output voltage.It is used the zero-calibration technology，the signal synthesis and the restoring technology to eliminate and control the voltage floating .