The invention provides a tool and method for eliminating connection gaps of high-pressure turbine rotor blades. The tool comprises an adjusting screw rod, an upper driving block, a squeezing block and a lower driving block. The squeezing block and the lower driving block are sequentially arranged on the adjusting screw rod in a penetration mode. When the adjusting screw rod is screwed, the upper driving block drives the adjusting screw rod to rotate to squeeze the squeezing block downward. The lower driving block drives the adjusting screw rod to rotate to squeeze the squeezing block upwards, so that the squeezing block protrudes outwards. In the method, the tool for eliminating the connection gaps of the high-pressure turbine rotor blades is adopted. By means of the tool and method for eliminating the connection gaps of the high-pressure turbine rotor blades, the connection gaps between the high-pressure turbine rotor blades and a turbine disk can be effectively eliminated, so that the diameter of high-pressure turbine blade tips is accurately obtained. The tool is simple in principle, simple in structure and low in manufacturing cost and maintenance cost.