As a new kind of swarm intelligent algorithm, fruit fly optimization algorithm(FOA) has been successfully applied in a variety of fields because of its simplicity and effectiveness. In this paper, a complete survey on FOA in aspect of the search mechanism, relative merits, improvements and applications is presented. The studies on FOA about its improvements including the search step size, solution generation mechanism, and multi-swarm strategies are especially discussed. The applications status of FOA in aspect of complex function optimization, combinatorial optimization, parameter optimization is summarized. Finally, some novel research directions about the improvements and applications of FOA are given.