The paper presents many kinds of experimental results and analysis in the experiment that PC HgCdTe detector is irradiated by 1.06μm laser.Results of optical effect,thermal effect and opto-thermal effect are given respectively.During irradiation,signal outputs of detector are due to competition between light and heat.After irradiation stopped,signal outputs of detector are due to detector thermal resuming.When temperature changes,there is a valley in optical response curve and a peak in thermal response curve.Temperature of detector,laser density and irradiated time are the key parameters that affect signal output of detector.