Abstract: The micro pin-fin structure opens up a new direction for solving the over-temperature problem of microelectronic equipment. In this paper, staggered micro pin-fins models with longitudinal spacing of 800 μm, 1 200 μm, and 1 600 μm, and cross-sectional shape of square and circular were established.Under the condition of 50≤Re≤600, the influence of different longitudinal spacing and cross-sectional shape on the flow characteristics in the staggered micro pin-fins were calculated and analyzed. The research results showed that: the smaller the longitudinal spacing is, the later the boundary layer separation occurs; the flow separation phenomenon of the square micro pin-fins were earlier than that of circular micro pin-fins; the asymmetry of a pair of vortices at the wall of micro pin-fin with smaller longitudinal spacing is more obvious; the pressure difference in the micro pin-fins is directly proportional to the flow velocity and inversely proportional to the longitudinal spacing; non-smooth structure of micro pin-fin can significantly increase the pressure drop in the micro pin-fins; the pressure difference of the staggered square micro pin-fin with a longitudinal spacing of 800 μm is 25% greater than that in the staggered circular micro pin-fin with a longitudinal spacing of 800 μm; f From the perspective of disturbance enhancement promoting fluid mixing, the square staggered micro pin-fin with a longitudinal spacing of 800 μm is the best.