The invention discloses a
model parameter training method based on federal learning, a terminal, a
system and a medium, and the method comprises the steps: determining a feature intersection of a first sample of a first terminal and a second sample of a second terminal, training the first sample based on the feature intersection to obtain a first mapping model, and sending the first mapping modelto the second terminal; receiving a second
encryption mapping model sent by a second terminal, and predicting the missing feature part of the first sample to obtain a first
encryption completion sample; receiving a first encrypted federal learning
model parameter sent by a third terminal, training a to-be-trained federal learning model according to the first encrypted federal learning
model parameter, and calculating a first
encryption loss value; sending the first encryption loss value to a third terminal; and when a training stopping instruction sent by the third terminal is received, takingthe first encrypted federal learning model parameter as a final parameter of the federal learning model to be trained. According to the invention, the
characteristic space of two federated parties isexpanded by using transfer learning, and the prediction capability of the federated model is improved.