In order to effectively solve the problems consisted in the method of existing network system fault detection

the problems includes that detection accuracy is not high

the detection convergence speed is slow

and its easy to fall into local optimum.In this paper combined with the Bat Algorithm(BA)and Quasi Newton(QN)strategy

a novel model of network system fault detection based on QN-BA is proposed.In this way

the optimal solution of the model is obtained by combining the filtering model and the residual error model

which can effectively avoid the existing problems.Finally through the simulation experiment obtained the fault detection performance index chart

and by comparing the NPSO-PF and LWRLR verify the effectiveness of the proposed approach.