Electricity market trade based on mobile intelligent device will extend the volume of transaction. For the massive and various trading data, transaction mining algorithm is very useful to find the relationship of correlative elements such as trade price and power capacity, and it always occurs between the power users and power generation enterprises. The novel FP-Table algorithm is proposed in this paper to solve the massive transaction mining problem. The FP-Table algorithm integrates the Hash table into FP-Growth algorithm, using two-dimension table saving frequency count of item pair, then mining the frequency items of electricity transactions efficiently. Application of mobile transaction mining is proved to be high efficiency and high value by performance experiment results.