An ocean single-element observation 
quality control method based on multi-model fusion adopts a four-layer 
model architecture combining 
statistical analysis and a single classification 
algorithm to detect whether historical 
observation data of a certain element of an ocean site is abnormal or not. The method comprises the following steps: S1, an input layer, which constructs three 
time windows from far to near for historical 
observation data of a certain element of a marine site, extracts statistical features, fits features and classification features, and constructs a detection sample; S2, a 
statistical analysis layer, which filters 70% of positive samples by using a statistical discrimination 
algorithm, reduces the scale of an abnormal candidate set, and effectively relieves the influence caused by imbalance of the positive and negative samples; S3, a single classification layer, which further detects the suspected abnormal 
observation data points by using a single classification model; and S4, the output layer, which is used for comprehensively making a final judgment according to results of the 
statistical analysis layer and the single classification layer, and evaluating a detection result. According to the method, the detection results of various models are comprehensively considered to make an 
optimal decision, so that the accuracy of the detection method is effectively improved.