Aiming at the defects of the basic fruitfly optimization algorithm (FOA)，the control accuracy was not high and easy to fall into local optimum, a method for parameter optimization of PID controller based on improved fruitfly optimization algorithm（IFOA）was proposed, in which absolute error and the square of control input were used as fitness function and the optimal PID parameter value was obtained through iterative optimization. Compared with the basic fruitfly optimization algorithm, the simulation results show that the algorithm has high control precision, fast response and robustness through two order delay system test. It provides a reference for PID parameter optimization.