Combining logical function and memory characteristics of transistors is an ideal strategy for enhancing computational efficiency of transistor devices. Here, we rationally design a tri-gate two-dimensional (2D) ferroelectric van der Waals heterostructures device based on copper indium thiophosphate (CuInP₂S₆) and few layers tungsten disulfide (WS₂), and demonstrate its multi-functional applications in multi-valued state of data, non-volatile storage, and logic operation. By co-regulating the input signals across the tri-gate, we show that the device can switch functions flexibly at a low supply voltage of 6 V, giving rise to an ultra-high current switching ratio of 10⁷ and a low subthreshold swing of 53.9 mV/dec. These findings offer perspectives in designing smart 2D devices with excellent functions based on ferroelectric van der Waals heterostructures.