The invention provides a neighbor projection type gradient coordination
compression method and device and a
federated learning system, and relates to the technical field of
federated learning. According to the method, the uploading gradient of the
client side is obtained, direction normalization is carried out, direction embedding updating of the
client side is carried out through index
moving average, then the similarity between the
client sides is calculated, a neighbor set is generated, a similar graph is constructed, and then conflict detection and weight setting are executed. And performing weighted orthogonal projection in the frozen neighbor direction of each client to correct the gradient, and finally performing weighted aggregation on the gradient and updating
global model parameters. According to the method, gradient conflicts are efficiently detected and corrected in a local range by constructing the client similar graph and combining a neighbor projection mechanism, the problems of
high complexity and excessive information reduction caused by global
processing are avoided, the convergence speed, stability and precision of a
global model are improved under the condition that additional calculation and communication overhead of the client is not increased, and the user experience is improved. The method is suitable for large-scale non-independent identically distributed data scenes.