The isomerization between dimethyldihydropyrene (DHP) and cyclophanediene (CPD) makes it be a potential molecular device, and topological regulation provided an effective strategy to tune its optical response and switching efficiency. In this work, we twisted fused pyridine structure into three topological configurations, namely, Hückel, Möbius and twisted-Hückel (t-Hückel), and integrated them at both ends of a DHP/CPD switch. By theoretical calculation, we noticed the effect of topological characteristics on molecular structure, electronic state and optical properties. Especially for Hückel and Möbius molecules, CPD was closed-shell state and DHP showed diradical property. However, for t¬-Hückel molecules, CPD and DHP were both open-shell singlet states. The topological effect was significant on absorption intensity at the range of 200~500 nm for both open- and closed-ring structures. Within the framework of Hückel, Möbius to t-Hückel, the βtot gradually decreased for closed-ring structures as the degree of twisting of the pyridine ring increases, but the tendency was opposite in open-ring systems. Consequently, Hückel-type switches demonstrated high efficiency, with a ratio of β(C)/β(O) = 12.6. DHP derivative with a Hückel-type molecules exhibit the best nonlinear optical response due to the highly conjugated structure with the largest first-order hyperpolarizability of closed-ring structure (βtot=1.03×105 a.u.). This work highlights the crucial role of topological structure in regulating the performance of switch molecules and provides insights for the design of switch molecules with unique topological structures.