Disclosed is a method of controlling an inkjet printing process. According to one embodiment of the present invention, a method of controlling an inkjet printing process by using an inkjet print system, the method including a printing operation of moving a first support chuck or a second support chuck in a second direction perpendicular to a first direction and performing the inkjet printing process of discharging an ink onto a substrate and a first suction operation of suctioning remaining ink from a nozzle formed on a first head or a second head using a first suction unit, wherein a controller controls the printing operation for a first substrate, the first suction operation for the second head or the printing operation for a second substrate, and the first suction operation for the first head to be sequentially performed.