The wide application of large-capacity cylindrical power batteries in electric vehicles has led to an increasingly demand on lightweight and thermal management design for battery pack.In this work,the newly 4680 large cylindrical batteries were taken as research object,four kinds of carbon fiber reinforced composite material (CFRP) cylinder heat dissipation structures with four different micro-channel networks (parallel,bifurcated,serpentine and spiral) were designed,and the influences of microchannel network structure,flow rate of coolant,microchannel diameter and the number of microchannel inlets and outlets on the heat dissipation were analyzed.The results show that the overall performance of the parallel network microchannels is the best among the four kinds of CFRP cylindrical cooling structures; the microchannel diameter offers little influence on the heat dissipation performance of the cylinder structure,but has great effect on the pumping pressure; the heat dissipation performance of the CFRP cylinder with two inlets and two outlets is obviously higher than that of CFRP cylinder with one inlet and one outlet.