Trust is helpful to the cooperation of enterprises. Different trust types can produce different cooperation efficiency. Cloud model is used to evaluate the trust degree among the enterprises in the demand-side food supply chain to help select the appropriate trust type. Trust decision logic is used to prove the correctness of trust type selections. The results show that the relational trust between food processors and producers is at a higher level, and the calculative trust is at a lower level, so the relational trust should be chosen; the relational trust between food processors and distributors is at a lower level, and the calculative trust is at a higher level, so the calculative trust should be chosen. The analysis of trust decision logic verifies the correctness of the research results.