It is difficult to construct smooth multi-wing chaotic systems. This paper proposes two novel smooth multisegment nonlinear functions based on a smooth algebraic function，and constructs two new chaotic systems， e.g.，a one-direction multi-wing S-M one and a two-direction grid multi-wing S-M one， by using the proposed multisegment nonlinear functions. Then，the nonlinear dynamic behaviors of two smooth multi-wing chaotic systems are analyzed， with phase diagrams，equilibrium points， invariance，dissipation，Lyapunov exponents，fractal dimension，Poincaré section，and the generation mechanism of the multi-wing chaotic attractors being obtained. The generation mechanism is that the saddle-focus equilibrium points with index 2 are responsible for generating wings. In addition， the circuit implementations of the one-direction multi-wing S-M chaotic attractors and the two-direction grid multi-wing S-M chaotic attractors validate theoretical results and numerical simulations.