Garlic is one of the species in onion genus, which has been used as both a flavoring agent and a complementary medicine. Although garlic has many active components that contribute to its health benefits, including allicin and its derivatives, consumption of unprocessed raw garlic is limited due to its characteristic odor, taste and tendency to cause stomach upset. Aged black garlic was prepared through natural fermentation of whole garlic at controlled high temperature and humidity, a process that resulted in black cloves. Aiming to obtain a non-fermented black garlic with low cost of ownership, which combined the steaming process with roasting process. The influences of steaming temperature, steaming time, roasting temperature and roasting time on preparation process for black garlic were investigated. The optimum processing parameters for the preparation of black garlic were determined by combined use of single factor and orthogonal experiments. The results showed that the optimal combination was steaming temperature of 127℃, steaming time of 70min, roasting temperature of 95℃ and roasting time of 6.5h. Under the optimum conditions, the black garlic had total phenols of 11.15mg/g, moisture of 27.41%, reducing sugar of 7.87g/(100g) and total acid of 36.09g/kg, reducing capacity of black garlic was more than 1.4 times of that of vitamin C in the 0.06~0.18mg/mL concentration range. This showed black garlic possessed strong antioxidant capacity. Compared with the fermentation process, the research significantly shortened the preparation time of black garlic, improved production efficiency, reduced energy consumption, provided technical basis for the development and utilization of functional garlic products.