To get a Multi scroll chaotic system with complex structure and good performance, based on theoretical analysis and simulation methods, a single direction and grid multi scroll model was presented by designing a continuous nonlinear function from a three order Chua system. Dynamic characteristics of multi scroll Chua chaotic attractor were analyzed by observing attractors phase diagram, bifurcation diagram, Poincaré section and calculating the largest Lyapunov exponent on the Matlab simulation platform. The research results show that the multi scroll chaotic attractors have rich dynamical characteristics. Simulation results are accordant with the theoretical analysis, which shows that the method of designing Multi scroll chaotic system is effective and the designed model is correct.