The invention provides a compressor air energy storage system. The compressor air energy storage system comprises a compression unit, an expansion unit, an air storage unit, a heat accumulation unit, a heat exchange unit and an electric power unit, wherein the compression unit comprises a low-pressure-level compressor set and a high-pressure-level compressor set; the expansion unit comprises a low-pressure-level expansion machine set and a high-pressure-level expansion machine set; the compression unit and the expansion unit form a combined structure; two co-rotation-shaft identical-model compressors or expansion machines which rotate oppositely form one set; one or more sets of machine sets operate parallelly as one stage; more than two stages of machine sets operate in series to jointly form the whole compression unit and the whole expansion unit; therefore, on one hand, energy storage requirement of various stages is favorably met, and on the other hand, the compressed air energy storage system is applicable to operation cycles of different lengths; and furthermore, axial force is favorably counteracted, and the stability of the whole system is improved.