For those problems arising from the motion state of the flow field and tangential leakage characteristics in the working cavity of a micro scroll compressor are hard to catch through experimental tests,taking the 3-D fluid model formed by the meshing of dynamic and static scroll disks with radial clearance as the research object,CFD dynamic mesh technology was applied to establish a structured mesh and define the marginal motion,the transient distributions of fluid in the working process of crescent compression cavity were explored.The transient distribution laws of temperature field,velocity field and pressure field in the compression working chamber caused by radial clearance were studied.The results show that the tangential leakage has a massive impact on the inhomogeneous distribution of temperature and velocity field,and it has a small influence on the pressure field,at the meshing gap,the pressure and temperature change in a gradient,and the velocity has an extreme value;the average inlet and outlet mass flows and leakage are directly proportional to the speed.