Many studies have illustrated that the turbine blade with a squealer tip has less aerodynamic loss than the one with a flat tip. However, there exists an area of high heat transfer coefficient (HTC) in the frontal region of the cavity floor. To solve the problem, Tthe present study concentrates on the effect of squealer-rim pressure-side groove structure on turbine blade aerothermal performance. Through the experimental and CFD results, it can be concluded that the case with a groove on the pressure side of the squealer rim has smaller area of high heat transfer coefficient region and the aerodynamic efficiency is raised. Meanwhile, the effect of different sizes of the groove is also investigated and it has a great impact on the heat transfer and aerodynamics. It is found that tThe mass flow passing through the groove can largely influence the flow field of the tip gap and the cavity. The heat transfer and the aerodynamic efficiency of the blade tip vary from the groove size.