Flow velocity uniformity of the microchannel plate is a major factor affecting the performance of microchannel devices. In order to improve the velocity distribution uniformity of the microchannel plate, we designed two new microchannel structures: V-type and A-type. The effects of various structural parameters of the manifolds on the velocity distribution are reported. The V-type and A-type microchannel plates had a more uniform velocity distribution compared to the Z-type microchannel plate. The final result showed that it is beneficial for the V-type microchannel plate to obtain a more uniform velocity distribution when the manifold structure parameters are X_in = -1, X_out = 0, Y_in = 10, Y_out = 6, H_in = 4, H_out = 1, and R = 0.5.