In order to study the influencing factors of the application of temperature difference in ship’s exhaust gas and to explore the potential of recycling waste heat from ship’s exhaust gas, an experimental system for temperature difference power generation in ship’s exhaust gas has been designed. Besides, related performance studies have been carried out about the characteristics of temperature difference power generation tablets and exhaust gas. Moreover, the theoretical calculation of the maximum output power and maximum efficiency of the individual temperature differential power generation module was carried out. Furthermore, the effects of insulation material, installation pressure, thermally conductive silicone grease, brine concentration, cooling water temperature, and heat source temperature on the performance of the individual temperature differential power generation module were thoroughly investigated. The results showed that the insulation material and the brine had a small effect on the efficiency of the differential temperature power generator. Conversely, the mounting pressure, the thermal grease, the cooling water temperature, and the heat source temperature greatly influenced the open-circuit voltage and the maximum output power. The installation pressure, the thermal grease, the cooling water temperature, and the heat source temperature increased the open-circuit voltage by 6.72%, 31.54%, 18.95%, and 26.92%, respectively, and increased the maximum output power by 15.63%, 82.05%, 51.79%, and 49.41%, respectively. The maximum output of a single temperature differential power generator reached 63.5% when using an installation pressure of 3 bar, a cooling water temperature of 20°C, double-layer aluminum insulation, a thermally conductive silicone grease, and a brine concentration of 5.5%. Finally, this study provides reference data support for the use of temperature differential power generation devices for ship exhaust gas and lays a foundation for the further research and development of this technology on ships.