The present invention discloses a refrigerant flow regulation device in high-capacity air-conditioning system. It is characterized by that in air-conditioning refrigeration and heat production system are parallelly set a low-capacity electronic expansion valve and a capillary tube, in which two ends of parallelly-connected low-capacity electronic expansion valve and capillary tube are respectively connected into refrigerant flow path of air-conditioning system. Said invention adopts the parallel connection of low-capacity electronic expansion valve and capillary tube to control flow quantity of refrigerant.