Traditional multi-class classification circuits mostly use the mechanism of winner-take-all. In this paper, a memristor-based classification circuit with the loser-take-all mechanism is designed. The winner-take-all mechanism selects the most active neuron or signal while suppressing others, whereas the loser-take-all mechanism suppresses the most active and amplifies weaker signals. The goal of the loser-take-all mechanism is to determine which class an item does not belong to, rather than to determine which class the item belongs to. The loser-take-all mechanism can use relatively undemanding criteria to correctly classify the majority of categories that are misclassified by the winner-take-all mechanism. The designed circuit includes input modules, control modules and suppression modules which realize the multi-classification function based on the loser-take-all mechanism. The simulation results in Cadence show that the circuit can be used to realize complicated classification applications. The memristor-based classification circuit with the loser-take-all mechanism can capture the subtle nuances of various categories and provide a flexible approach to classification tasks.