The embodiment of the invention provides a data transmission method and device and an electronic device. The data transmission method comprises the following steps: receiving data requests sent by a plurality of user terminals; determining the current data storage condition of each user terminal, wherein the data storage condition comprises whether each user terminal stores each piece of target data and the information age of the target data stored in each user terminal; determining an optimization equation of the minimum expected energy consumption according to the current data storage condition of each user terminal, the storage space of the user terminal and a preset age threshold; and based on the optimization equation of the minimum expected energy consumption, determining a path foreach user terminal to obtain the required target data, the path comprising: obtaining the required target data from the information source or obtaining the required target data from other user terminals. Therefore, the information source can comprehensively consider the storage condition and the storage space of the user terminal and the information age of the target data, and formulate a reasonable data distribution scheme, so that the user terminal obtains fresh real-time information.