A radio frequency identification reader anti-collision optimization model is studied for Internet of things, which considers minimizing reader conflicting and total processing time. Based on the standard particle swarm algorithm, we propose a new anti-collision model on account of biological symbiosis theory of the nature. It defines the information communication mechanism of cooperation in single species and collaboration between species, so that symbiotic strategy in ecological system is established. It has better diversity keeping ability and searching performance. The simulation result shows that our proposed algorithm can effectively solve reader collision problem in intensive reader environment and optimize the efficiency of the whole reader network.