The invention discloses a data storage method and device, a server and a storage medium, and belongs to the technical field of Internet. The method comprises the steps that when a write-in request forfirst data is received, inquiring the storage position of second data; when it is queried that the second data is stored in the first cache unit, storing the first data in the second cache unit; andreturning a writing result of the first data. According to the invention, the data is stored based on the first cache unit and the second cache unit; a data storage mode of independently adopting a second cache unit is adopted; cost is saved, for the data stored in the first cache unit, the data is stored in the second cache unit; when the data is stored again, the data is stored in the second cache unit, the data reading and writing speed is increased, the data writing frequency of the first cache unit is reduced, the first cache unit is prevented from being damaged, the data safety is improved, and the mode gives consideration to the requirements for cost, the data reading and writing speed, the data safety and the like.