All indicators of the dual flow laser dust particle counter are calibrated according to the JJF 1190-2008 dust particle counter calibration specification issued by the General Administration of Quality Supervision, Inspection and Quarantine of China. The entire machine is controlled and processed by a microcomputer, and the test results can be directly printed, which is very convenient for researching, testing and evaluating various clean environments. This instrument also has a purification level alarm function, which can be applied to clean room cleanliness monitoring. Therefore, this instrument can be widely used in industries and departments such as microelectronics, medical pharmaceuticals, biochemical products, blood products, food hygiene, cosmetics, precision machinery, fine chemicals, and aerospace.