The DSMC (Direct Simulation Monto-Carlo) computer code of a small nozzle vacuum plume was reformed.The computation showed that parallel computing could greatly accelerate computation

shorten computing time and enlarge computing scale.The parallel computation results accorded well with the sequential computation results.An example of DSMC parallel computation was also completed successfully for a vacuum plume and the computation results agreed well with theoretical analysis.The sequential computation won't be able to cope with this task.