1. A carrier selection method for a logistics network, the logistics network comprising a plurality of carrier sets having a plurality of carriers, a start, a terminal and a plurality of routes between the start and the terminal, the routes formed as a plurality of minimal paths, wherein the carrier selection method is applied for finding an optimal carrier set with a maximal network reliability from the carrier sets, and comprises the steps of: choosing one of the carriers through each of the routes to form one of the carrier sets for transporting a transmission in the logistics network; distributing a demand of the transmission to the minimal paths, wherein each of the carriers has a plurality of cargo capacities and a maximal capacity; evaluating the network reliability for each of the carrier sets according to the demand, the cargo capacities and the maximal capacity; and executing a genetic algorithm to search for the optimal carrier set among the carrier sets, wherein the optimal carrier has the maximal network reliability.