Abstract: In order to explore the optimum parameters of HTSTSB on passivating POD of maca, and solve the browning of maca in processing, response surface methodology(RSM) was employed to construct a quadratic regression model describing the effects of treatment time, steam pressure and spheroniser load on the relative activity of POD in maca. The optimization results showed that the optimum conditions were 0.3MPa of steam pressure and 170g of spheroniser load for 54s, relative activity of POD in maca was 4.9%. After 7 d, the browning rate of unhandled maca was 52.66%, the loss rate of glucosinolates, alkaloid, VC and total phenols were 45.68%, 13.71%, 20.27% and 15.13%.However, at high temperature and steam blanching, the browning rate of maca was only 8.56%, the loss rate of glucosinolates, alkaloid, VC and total phenols were 23.46%、11.29%、6.76% and 10.26%. It showed that the browning of maca could be effectively controlled, the nutrients could be well preserved.