In this paper, we investigated the impact of saturable absorber parameters (including the modulation depth, nonsaturable absorption and saturation intensity) in passively mode-locked fiber laser. Numerical simulations show that these parameters can influence the dissipative solitons’ physical properties. According to our results, we can deeply understand the importance of saturable absorber to passively mode-locked fiber laser and develop a more suitable two-dimensional material used as a saturable absorber in experiments based on the analysis of saturable absorber parameters.