The present invention relates to a scroll compressor (100). The scroll compressor comprises a shell (10); a fixed scroll component (80) and a moving scroll component (70) arranged in the shell, wherein the fixed scroll component is fixed relative to the shell, and the moving scroll component can float in the axial direction relative to the fixed scroll component; a main bearing base (40) is arranged in the shell to support the moving scroll component, a back pressure cavity (B) is formed between the moving scroll component and the main bearing base and communicated with fluid of a compression cavity (C2) through a communication channel (73), the communication channel (73) is formed in the moving scroll component, and the compression cavity (C2) is formed between the fixed scroll component and the moving scroll component; and valve components (90, 90A) arranged in the communication channel (73) are formed to respond the pressure difference between the compression cavity and the back pressure cavity so as to provide a first aperture and a second aperture, and the second aperture is smaller than the first aperture.