Memristors, as a new generation of non-volatile memory, can simulate biological synapses. Current research on memristor dielectric materials primarily focuses on transition of metal oxides, perovskites, and organic polymers. Among these, the transition metal oxide TiO₂ is widely used for the switching layer due to its high dielectric constant and excellent thermal stability. However, TiO₂-based memristors face challenges including poor stability and inadequate analog performance, which fundamentally limit their applicability in neuromorphic computing. In this study, a high-performance analog memristor is developed using an a-MoS₂/a-TiO₂ (amorphous MoS₂/amorphous TiO₂) heterostructure, achieving over 200 stable cycles and a long data retention time exceeding 10⁴ s. This device exhibits a lower threshold voltage, higher endurance, and excellent data retention compared with previously reported TiO₂-based heterostructure memristors. Furthermore, various voltage sweep schemes are designed to successfully modulate multi-level conductance in the W/a-MoS₂/a-TiO₂/Pt device. The resistive switching mechanism of the W/a-MoS₂/a-TiO₂/Pt device is elucidated by combining conductive mechanism fitting with a physical model that attributes the switching to the localized formation and rupture of conductive filaments. Finally, synaptic functions such as LTP and LTD are achieved in the device by using square-wave pulses. In this study, a W/a-MoS₂/a-TiO₂/Pt heterostructure is developed, which significantly enhances analog memristive performance and provides an effective strategy for improving transition metal oxide-based memristors.