The invention discloses a virtual machine migration compression method and system based on bandwidth perception and belongs to the field of computer virtualization. According to the method, preset frequency detection network bandwidth and each pair of compression rate and compression speed in a compression strategy table are utilized to calculate migration speeds; a compression method corresponding to the maximum migration speed is selected to perform migration compression; and before memory data compression is performed, multiple memory pages are combined into a data packet first, and then the data packet is subjected to integral migration compression till migration compression is completed. Meanwhile, the invention furthermore provides the virtual machine migration compression system based on bandwidth perception. According to the technical scheme, the compression method is adjusted dynamically according to the bandwidth to allow a migration system to obtain a higher migration speed, and therefore shorter migration time is obtained; meanwhile, the data transmission amount is reduced, and network resources are saved.