(HgCd)Te detectors have strong Franz Keldysh (F-K) effect and the effective intensity of F-K effect of the (HgCd)Te detector has close relation to bias voltage,. According to this principle, electronic circuit of controlling (HgCd)Te detector′s photon absorption coefficient has been designed and fabricated. Experimental results show that the module composed of a photon absorption coefficient controller and (HgCd)Te detectors can meet the needs of practical application in some extent.