In recent years, optical vortex arrays have attracted increasing attention for their potential applications in numerous areas, such as optical communications, multiple-particle manipulation and parallel laser fabrication. However, the generation of switchable longitudinal vortex arrays remains a great challenge. In this paper, a liquid crystal (LC) spiral Dammann zone plate is designed via the Dammann encoding method and fabricated via the LC photoalignment technology. The experimental results show that this device can create a 1×5 longitudinal vortex array with high efficiency, and with space-variant topological charges. Through tuning the applied voltage, the device can be switched between ON and OFF state dynamically. Besides, the topological charges of the generated longitudinal vortex array can undergo a reversal or additive transformation by horizontally/vertically flipping the device or altering the mode of incident light. The LC spiral Dammann zone plate is distinguished by low cost, high efficiency and electro-optical tunability, thus facilitating the applications of LC elements in the field of multi-dimensional beam shaping.