NOVELTY - Producing optically active alcohol through asymmetric reduction of prochiral ketone by yeast resting cell in a cloud point system comprises: (a) culturing and fermenting the yeast cell to obtain wet bacteria and directly using it as a biological catalyst; (b) using prochiral ketone as the substrate for the conversion; (c) adding the wet bacteria obtained in (a) to the cloud point system solution and adding the substrate to perform the conversion so as to produce corresponding optically active alcohol; and (d) centrifuging the conversion solution to get rid of the cell.    USE - The method is useful for producing optically active alcohol through asymmetric reduction of prochiral ketone by yeast resting cell in cloud point system (claimed).    ADVANTAGE - The method removes the inhibiting effect of insoluble substrate and product to the reaction by a large extent so as to perform the conversion under a relatively high concentration. The conversion efficiency of the substrate is high enough to realize multiple circulation of the cell for second use. The reaction conditions are moderate, and environment-friendly so the method has pretty high pragmatic utilization valve and development prospect.    DETAILED DESCRIPTION - Producing optically active alcohol through asymmetric reduction of prochiral ketone by yeast resting cell in a cloud point system, where the method uses one or more non-ionic surfactant solution to form the cloud point system to use as the medium for bioconversion, comprises: (a) culturing and fermenting the yeast cell to obtain wet bacteria and directly using it as a biological catalyst; (b) using prochiral ketone as the substrate for the conversion; (c) adding the wet bacteria obtained in (a) to the cloud point system solution and adding the substrate to perform the conversion so as to produce corresponding optically active alcohol; and (d) after the finish of the conversion, centrifuging the conversion solution to get rid of the cell; then placing the supernatant in a water bath and slowly raising the temperature of the water bath until the solution gradually changes from homogeneous phase to be turbid and further laminated to form two stable coexisting phases, the upper layer is a diluted phase and the lower layer is a coagulation phase.