Numerous studies have been conducted to explore the performance of two-dimensional (2D) layered nano-materials based saturable absorber (SA) for pulsed laser applications. However, fabricating materials in nanoscale requires complicated preparation processes, high energy consumption, and high expertise. Hence, the study of pulsed laser performance based on the saturable absorber prepared by layered materials with bulk-micro size have gained a great attention. Platinum disulfide (PtS2), which is newly developed group 10 2D layered materials, offers great potential for the laser photonic applications owing to its high carrier mobility, broadly tunable natural bandgap energy, and stability. In this work, the first passively Q-switched Erbium (Er) doped fiber laser is demonstrated with an operational wavelength of 1568.8 nm by using PtS2 microflakes saturable absorber, fabricated by a simple liquid exfoliation in N-Methyl-2-pyrrolidone (NMP) and then incorporated into polyvinyl alcohol (PVA) polymer thin film. A stable Q-switched laser operation is achieved by using this PtS2-SA within a fiber laser ring cavity. The maximum average output power is obtained as 1.1 mW, corresponding to the repetition rate of 24.6 kHz, the pulse duration of 4.2 μs, and single pulse energy of 45.6 nJ. These results open up new applications of this novel PtS2 layered material.