The invention provides a disk physical block allocation method for a host machine system with a virtual machine and equipment; the existing host machine system does not take whether all the virtual blocks to be written-in belong to the relation of the same file into account when the corresponding physical block is allocated to the virtual block to carry out write operation, therefore, a plurality of the virtual blocks which belong to the same file are usually dispersed to the discontinuous position of a physical disk; the proposal provided by the invention can analyze the virtual blocks to be written-in to recognize whether the virtual blocks belong to the same file and allocate continuous physical blocks to the virtual blocks belonging to the same file, thereby avoiding that the same file is dispersedly stored in the discontinuous physical disk blocks.