The nozzle arrangement of internal spray cooling tool plays a crucial role in the e ciency of coolant ow into the cutting zone and has a signi cant impact on the cutting performance. This article designs three types of internal spray cooling turning tools based on the different arrangements of the upper nozzle on the tool rake face. Tool A has an upper nozzle near the main cutting edge, tool B is equipped with an upper nozzle near the minor cutting edge, and tool C possesses two upper nozzles near the main and minor cutting edges respectively. The nozzle arrangement effect on the cooling performance of the internal spray cooling turning tool during the internal turning process was studied by the uid-solidthermal coupling simulation method. The simulation results showed that tool B with an upper nozzle arranged near the minor cutting edge had the best cooling performance because it is easy for air and coolant droplets to enter the tool-chip contact zone. On the contrary, tool C equipped with two upper nozzles near the main and minor cutting edges results in the worst cooling performance for the air and coolant droplets are di cult to ow into the tool-chip contact area. Internal turning experiments of QT500-7 workpieces were carried out. Results demonstrated that tool B performed best in reducing cutting temperature and improving machined surface quality. In addition, the number of small chips generated by all internal spray cooling turning tools increased at an inlet pressure of 0.6MPa, especially for tool B.