Taken the operational amplifier as the active devices, the saturated nonlinear function series circuit is designed, and the critical circuit frequency is determined. The saturated nonlinear function series circuit is applied into the multiscroll chaotic circuit, and the influence of the amplitude, width, slope of the saturated nonlinear function series on multiscroll chaotic attractor is also investigated. Moreover, a parameter adjustable chaotic circuit is designed based on the saturated nonlinear function series. The results show that the size and shape of the multiscroll attractors can be adjusted by changing parameters. The designed saturated nonlinear function series circuit is stable and flexible, and it is propitious to the application of multiscroll chaotic circuit.