To establish a one-dimensional calculation model of a latticework of turbine blades, the flow exchange process and corresponding heat transfer characteristics between latticework subchannels are studied by numerical simulation, and the influence of latticework geometric characteristics and inlet Reynolds number on the flow exchange process was summarized. It is found that the blocking effect of the transverse vortex at the inlet of the subchannel and the stagnation effect of the subchannel with a small length-diameter ratio lead to the flow loss at the inlet of the subchannel. When the length-diameter ratio of the subchannel increases, the flow loss at the inlet of the subchannel decreases. The throttling effect of the turning channel leads to the flow exchange between the subchannels, and only the flow exchange is performed on the three adjacent interfaces before and after the turning channel. The flow exchange value of the subchannel is 30% ~ 80% of its average flow. As it approaches the turning channel, the flow exchange ratio of each interface is 1:3:6 in turn. The inlet Reynolds number does not affect the flow exchange process between subchannels. The increase in rib angle will enhance the flow exchange between subchannels. When the subchannel height ratio increases, the flow exchange process between the subchannels first increases and then decreases. The heat transfer intensity and flow resistance coefficient in the subchannel are proportional to the change in flow rate. Finally, the flow exchange calculation model of the latticework subchannel is established, which provides the basis for building the one-dimensional calculation model of the latticework duct.