The invention relates to a blanking method in picosecond laser closed graph glass cutting. In the picosecond laser glass cutting process, divisional plane gaps of picosecond laser cutting glass are small, so that blanking is difficult after closed graphs are accurately cut. In mobile phone touch screen glass cutting process, cutting gaps are frequently and artificially widened as a blanking problem exists, so that machining efficiency is greatly reduced or cracks at the edges of glass are increased, glass strength is reduced, and machining yield is reduced. According to the blanking method, in glass machining process of closed graphs cut by picosecond laser, temperature of glass before being cut and temperature of glass after being cut are controlled, temperature difference and pressure difference of double surfaces of the glass are controlled, so that automatic blanking is achieved, and machining requirements are met. According to the blanking method, blanking difficulties are improved in the cutting process of mobile phone touch screen glass, cutting efficiency is greatly improved, and cutting yield is stable.