It will consume lots of energy when the apps download mass data in the smartphone. Furthermore, the apps will increase the burden of the battery if they download big data with slow network. The paper proposes a smartphone download strategy that downloads mass data with appropriate delay to achieve low energy consumption. The strategy, called CLSA, selects the best download model that based on the current network situation, the length of download requests' queue and the local information of smartphone. We evaluate the CLSA using a music player implementation on a modern smartphone and compare it with the other two download strategies, Minimum Delay and WiFi Only. The result shows that the CLSA can achieve the optimal energy-delay trade off performance than the other two.