After the occurrence of the M_s7.0 Lushan earthquake on April 20, 2013, many media pointed that the occurrence of the Lushan earthquake was related with Three Gorges reservoir or Zipingpu reservoir or Pubugou reservoir, and so on. However, the qualitative arguments cannot give a reasonable conclusion. So, according to the previous studies, the analytic method is adopted to quantitatively analyse the impact of the Three Gorges reservoir, Pubugou reservoir and Zipingpu reservoir on the hypocenter of the M_s7.0 Lushan earthquake. The changes of elastic stresses and pore pressure of each reservoir to the M_s7.0 earthquake are calculated, respectively. The initial results indicated that the elastic stress changes induced by the Three Gorges or Pubugou or Zipingpu reservoirs are only dozens of Pa. When the diffusion coefficient is less than 1m²/s, the pore pressure changes of the hypocenter of the M_s7.0 Lushan earthquake are equal to zero, which means that the impoundment of the three reservoirs had no effect on the M_s7.0 Lushan earthquake. When there is a fault with a high permeability (diffusion coefficient is larger than 10m²/s) and extension of more than 100 km, the pore pressure changes of the hypocenter of the M_s7.0 earthquake could reach 3.2kPa and the coulomb stress change is 1.9 kPa. However, such a fault seems exceedingly unlikely. When a larger appropriate diffusion coefficient (1m²/s) is selected and 100 years filling of all the three reservoirs are supposed, the pore pressure and coulomb stress changes reached only several kPa. So, it can be confirmed that the impoundment of Three Gorges reservoir or Zipingpu reservoir or Pubugou reservoir is irrelevant to the occurrence of the M_s7.0 Lushan earthquake.