A refrigerant filling rotary compressor includes a shell, a compressing mechanism, an injection tube and an injection valve assembly. The compressing mechanism includes a cylinder, a main bearing, an auxiliary bearing, a crank shaft, a piston and a sliding vane. An inner wall of the cylinder chamber of the cylinder is formed with a filling mouth, and the cylinder is provided with a filling channel with a filling hole. The injection valve assembly is in a closed state when a pressure inside the cylinder chamber is higher than that in the filling hole so as to separate the filling hole from the filling mouth, and the injection valve assembly is in an open state when the pressure inside the cylinder chamber is lower than that in the filling hole so as to communicate the filling hole with the filling mouth, in which when the injection valve assembly is in the closed state, a space between the injection valve assembly and the filling mouth where a compressed gas exists is termed a clearance volume formed by the injection valve assembly, and a ratio between the clearance volume formed by the injection valve assembly and a reserve volume of the cylinder ranges from 0.3% to 1.5%.