Cognitive bias is one of the important reasons for the emergence， development and persistence of depressive symptoms. More and more researchers combine multiple cognitive biases for in-depth exploration. The cognitive bias of patients with depression mainly includes attention， interpretation and memory bias， which are independent and related to each other. Some studies have shown that attention bias is directly or indirectly related to memory bias through interpretation bias， and the combination of multiple cognitive biases can more significantly predict depressive symptoms than single cognitive bias. This paper summarizes the cognitive bias of patients with depression， the related theories of combined cognitive bias， the specific relationship between various cognitive biases and its impact on depressive symptoms