Bismuth sulfide (Bi₂S₃) is a promising non-tellurium candidate for thermoelectric application due to its low thermal conductivity and abundance of low-toxicity elements. In this work, Bi₂S₃-based materials are fabricated by combining mechanical alloying, high-pressure and high-temperature treatment, and spark plasma sintering (MA ​+ ​HPHT ​+ ​SPS). Cation and anion doping (copper and chlorine) are then employed to enhance the thermoelectric properties. While chlorine doping can effectively improve the electrical transport properties of Bi₂S₃, it results in a corresponding increase in thermal conductivity. Upon copper doping, the electrical properties show a moderate and steady improvement, which also plays a role in reducing thermal conductivity. Thus, the collaborative optimization of electrical and thermal properties is achieved, whereby a maximum zT value of 0.45 is finally obtained for the Bi₂S₃-0.25 ​mol% Cu sample at 573 ​K.