A small data backup algorithm based on memory chip is designed and implemented in many single chip microcomputer systems.The small data backup algorithm introduced in this paper uses the mapping relationship between time point and storage location, which makes data storage and query simple and fast,and does not need to use multiple cycles to find storage location and query point in the whole chip range,effectively overcoming the bottleneck of limited resources and slow processing speed of single chip microcomputer. This algorithm has been successfully used in a comprehensive meteorological data collector.From the situation of 200 collectors running continuously for two years,the data storage effect is good,and the data reading and storage are convenient,fast and effective.