In terms of single factor alkali peeling test of peony seed oil, this paper experimentally examined the effect of the variety of alkaline, the concentration of alkaline, heating duration, heating temperature on oil yield, in terms of peony seed oil quantities as testing index. Orthogonal test to key factors was carried out. It was concluded that the peony seed yield was affected in the order of lye concentration, heating time and heating temperature. The optimum processing conditions was as follows: 9% aqueous sodium hydroxide, 5min heating time and 80 ℃ heating temperature. At this condition, the peony seed yield reached 83.61%.