In 3D IC architecture, the thermal and power noise problems affect the performance of the whole chip. In this paper, we present a method to solve these two problems by simultaneously adding thermal TSVs (T-TSVs) for the thermal issue and decoupling capacitors (decaps) for the power noise issue. Since the unit-area capacitance of a T-TSV at the room temperature is equivalent to that of a decap, and the unit-area capacitance of a T-TSV is arisen with increasing temperature, T-TSVs have the abilities of dissipating thermal and reducing power noise. We formulate these two abilities into a linear programming. Without enlarging the floorplan area, the proposed method can alleviate the temperature and voltage drop using linear programming under the given target temperature and the threshold of the voltage drop. Experimental results show that the maximum temperature and average temperature can be reduced 48% and 29%. The voltage drop can be reduced 273% and all voltage drops are lower than 0.3 voltages.