In online sharing economy platforms, users often need to cooperate with strangers with minimal information. When personal photos are available on these platforms, how do users form social perceptions and consequently cooperative intention? According to the stimulus-organism-response (S-O-R) model and the kin selection theory, the authors propose that facial resemblance between two partners affects their perceptions of the cognitive trustworthiness, affective trustworthiness, attractiveness, and sociability of the partner, and that these social perceptions affect their cooperative intention. In the experiment, subjects evaluate the face of five potential partners of various levels of facial resemblance. The results support that the effect of facial resemblance on cooperative intention is mediated by social perceptions. Moreover, the transactional values and social values of the task partially moderate the effect of facial resemblance on social perceptions for female subjects. Sharing economy platforms may leverage the facial resemblance to facilitate cooperation among strangers.