Thermoelectric cooling, power generation and heat flow measurement are widely used in frontier domains while each of them is still in an isolated state. They are now widely used in fields such as electronic cooling, wearable device, sensors and so on. This paper proposes a method of thermoelectric effect combined with pulse width modulation (PWM) to achieve integrating thermoelectric applications. In a PWM cycle, the integration of thermoelectric applications makes it possible to realize three different operations of temperature control, energy recovery and heat flow measurement through a single thermoelectric module. The experimental results indicate that increasing the input voltage of the thermoelectric module extends the duration for power generation and heat flow measurement, while also enhancing the energy recovery rate. When the target temperature is higher than the ambient temperature, although the temperature control accuracy slightly decreases with the increase of the target temperature, the average temperature fluctuation range of the whole experimental group is −0.09∼+0.1℃ and energy recovery rate increases by 79.9 %. When the target temperature is lower than the ambient temperature, the system can still achieve efficient energy recovery. Applying the method to the computer central processing unit(CPU), the experimental results present that the heat dissipation of CPU can be monitored by measuring heat flow. Compared with the CPU + FPU working, the total power generation is increased by 0.285 W and energy recovery rate is increased by 78.3 % when the CPU is idle.